阅读说明：本技术 具有气密光启动器及外部阵列波导光栅的光发射次模块 (Optical transmitter sub-module with airtight optical initiator and external array waveguide grating ) 是由 林恺声 刘凯文 何宜龙 于 2019-08-29 设计创作，主要内容包括：本发明公开一种光发射次模块,根据本发明的光发射次模块包括耦接于气密光启动器的光驱动电路。气密光启动器包括由多个侧墙界定的壳体。壳体界定出气密的腔体以避免引入会降低光学能量的污染物。气密的光启动器通过光学插座光学地耦接于外部的阵列波导光栅或其他多工装置。光学插座例如包括光学隔离器、光纤柱及光纤套管部。因此,相较于将阵列波导光栅及相关的元件设于气密腔体内的方法,外部的阵列波导光栅及相关的外部光学耦合元件有利于使气密的光启动器具有尺寸较小的腔体。本发明还公开一种具有光发射次模块的光收发器。(The invention discloses a transmitter optical subassembly, which comprises a driver circuit coupled to an airtight optical starter. The hermetic light starter includes a housing defined by a plurality of side walls. The housing defines an airtight chamber to avoid the introduction of contaminants that would degrade optical energy. The hermetic optical actuator is optically coupled to an external arrayed waveguide grating or other multiplexing device through an optical receptacle. The optical receptacle includes, for example, an optical isolator, a fiber post, and a fiber ferrule portion. Thus, the external AWG and associated external optical coupling element facilitate a hermetically sealed optical actuator having a smaller cavity size than a method of locating an AWG and associated components within a hermetically sealed cavity. The invention also discloses an optical transceiver with the optical transmitter sub-module.)

1. A tosa, comprising:

the optical transmitter comprises an airtight optical starter and a plurality of laser devices, wherein the airtight optical starter is provided with a shell and the laser devices, the shell defines an airtight cavity, and the laser devices are arranged in the airtight cavity and are used for emitting a plurality of related channel wavelengths; and

a multiplexer disposed outside the hermetically sealed cavity and optically coupled to the hermetically sealed optical initiator to receive the associated channel wavelengths and output a multi-tap signal.

2. The tosa of claim 1, further comprising an optical coupling receptacle mounted to the hermetic optical initiator, the optical coupling receptacle including a waveguide provided at least in part by a fiber stub located outside the hermetically sealed cavity.

3. The tosa of claim 1, further comprising:

a substrate defined by a first surface and a second surface opposite to each other, the substrate comprising an electrical coupling area for electrically coupling to a transmission connection circuit and an optical initiator interface area for electrically coupling to the hermetic optical initiator; and

a light starter driving circuit disposed on the substrate for providing a radio frequency signal and a power signal to drive the hermetic light starter to output one or more channel wavelengths;

the substrate comprises at least one first circuit and at least one second circuit, the at least one first circuit is arranged on the first surface to provide the power signal, the at least one second circuit is arranged on the second surface to provide the radio frequency signal, and the first circuit and the second circuit are arranged in a mutually opposite mode to provide electrical isolation so as to reduce electrical interference between the power signal and the radio frequency signal.

4. The tosa of claim 3, further comprising at least one first interconnection device of a first type electrically coupled to the first line and a corresponding line in the housing of the hermetically sealed optical initiator to provide the power signal and at least one second interconnection device of a second type electrically coupled to the second line and a corresponding line in the housing of the hermetically sealed optical initiator to provide the rf signal, wherein the at least one first interconnection device of the first type is different from the at least one second interconnection device of the second type.

5. The tosa of claim 4, wherein the first interconnect device of the first type is a dc bus interconnect.

6. The tosa of claim 4, wherein the second interconnection means of the second type is a wire bond.

7. The tosa of claim 3, wherein the electrical isolation is provided at least in part by a width of the substrate and/or material properties of a material forming the substrate.

8. The tosa of claim 3, further comprising a plurality of electrical interconnects supporting the substrate in the housing of the hermetic light initiator.

9. The tosa of claim 3, wherein the housing of the hermetically sealed light initiator further comprises a feed-through device to electrically couple the laser devices to the hermetically sealed light initiator.

10. The tosa of claim 9, wherein the feedthrough is configured to be directly coupled to the substrate in an end-to-end connection.

11. The tosa of claim 9, wherein the feedthrough is defined by at least a first surface opposite a second surface, and the first and second surfaces of the feedthrough extend substantially parallel to the first and second surfaces of the substrate.

12. The tosa of claim 11, further comprising at least one line for receiving the power signal from a portion of the optical initiator drive circuit disposed on the first surface of the feedthrough device and at least one line for receiving the rf signal from a portion of the optical initiator drive circuit disposed on the second surface of the feedthrough device.

13. An optical transceiver, comprising:

a housing;

a transmitter optical subassembly disposed in the housing, the transmitter optical subassembly comprising:

the optical transmitter comprises an airtight optical starter, a laser device and a light source, wherein the airtight optical starter is provided with a shell which defines an airtight cavity and at least one laser device arranged in the airtight cavity; and

an arrayed waveguide grating disposed outside the hermetically sealed cavity and optically coupled to the hermetically sealed optical actuator for receiving a plurality of associated channel wavelengths and outputting a multi-tap signal; and

a light receiving sub-module disposed on the housing.

14. The transceiver of claim 13, wherein the tosa further comprises an optical coupling receptacle mounted to the hermetic optical initiator, the optical coupling receptacle including a waveguide provided at least in part by a fiber stub outside of the hermetically sealed cavity.

15. The transceiver of claim 13, wherein the tosa further comprises:

a substrate defined by a first surface and a second surface opposite to each other, the substrate comprising an electrical coupling area for electrically coupling to a transmission connection circuit and an optical initiator interface area for electrically coupling to the hermetic optical initiator; and

a light starter driving circuit disposed on the substrate for providing a radio frequency signal and a power signal to drive the hermetic light starter to output one or more channel wavelengths;

the substrate comprises at least one first circuit and at least one second circuit, the at least one first circuit is arranged on the first surface to provide the power signal, the at least one second circuit is arranged on the second surface to provide the radio frequency signal, and the first circuit and the second circuit are arranged in a mutually opposite mode to provide electrical isolation so as to reduce electrical interference between the power signal and the radio frequency signal.

16. The transceiver of claim 15, wherein the tosa further comprises a plurality of first interconnects to provide the power signal from the pump driver circuit to the at least one laser device of the hermetically sealed cavity, and the first interconnects support the hermetically sealed pump actuator on the substrate.

17. The transceiver of claim 15, wherein the tosa further comprises a dc bus disposed on the first and second surfaces of the substrate.

18. The transceiver of claim 15, wherein the tosa further comprises a plurality of second interconnects for providing the rf signal from the optical initiator driver circuit to the at least one laser device of the hermetically sealed cavity, and the second interconnects are bonding wires.

Technical Field

The present invention relates to U.S. patent application 15/963,246 ("TOSA with Trace Routing to Providede electric Isolation Between Between Power and RF Trace", filing date: 2018, 4, 26), the entire contents of which are incorporated herein by reference.

The present invention relates to optical communications, and more particularly, to a Transmitter Optical Subassembly (TOSA) having a hermetically sealed optical actuator housing and an Arrayed Waveguide Grating (AWG) of the hermetically sealed optical actuator housing.

Background

Optical transceivers may be used to send and receive optical signals for a variety of applications including, but not limited to, network data centers (internet data centers), cable TV broadband (cable TV broadband), and Fiber To The Home (FTTH). For example, transmission with an optical transceiver may provide higher speed over longer distances than transmission with copper cables. To provide higher speed in smaller optical transceiver modules at lower cost, challenges such as thermal management (thermal management), insertion loss (insertion loss), and yield (manufacturing yield) are encountered.

An optical transceiver module generally includes one or more tosas for transmitting optical signals. The tosa can include one or more lasers and associated circuitry for emitting one or more channel wavelengths (channel wavelengths) and for driving the lasers. Some optical applications, such as long-distance communications, require an tosa including a hermetically sealed housing and an awg, a temperature control device, a laser package (laser package), and associated circuitry disposed in the housing to reduce losses and ensure good performance. However, the inclusion of a hermetically sealed housing adds complexity and cost to manufacturing and leads to non-negligible (non-visual) challenges.

Disclosure of Invention

According to one aspect of the invention, an tosa is disclosed. The tosa includes a hermetically sealed optical initiator and a multiplexer. The airtight optical initiator has a housing and a plurality of laser devices. The shell defines an airtight cavity. The laser device is disposed in the hermetically sealed cavity and is configured to emit a plurality of associated channel wavelengths. The multiplexer is disposed outside the hermetic chamber and optically coupled to the hermetic optical actuator for receiving the associated channel wavelength and outputting a multi-tap signal.

The foregoing summary, as well as the following detailed description of the embodiments, is provided to illustrate and explain the principles and spirit of the invention, and to provide further explanation of the invention as claimed.

Description of the drawings:

fig. 1A and 1B are block diagrams of a multi-frequency optical transceiver according to an embodiment of the invention;

FIG. 2A is a perspective view of a first side of a tosa according to an embodiment of the present invention;

FIG. 2B is a perspective view of a second side of the tosa of FIG. 2A according to an embodiment of the present invention;

FIG. 2C is an enlarged view of a second side of the tosa of FIG. 2B according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view of a hermetic housing according to an embodiment of the invention;

FIG. 4 is another cross-sectional view of the hermetic housing according to the present invention;

FIG. 5 is a cross-sectional view showing the use of a hermetic housing according to the present invention with a fiber optic receptacle;

FIG. 6 is a perspective view of a hermetic housing according to the present invention;

description of the symbols:

100. 100' optical transceiver

102 shell

104 transmitting connection circuit

108 receiving connection circuit

110. 112 MPO connector

111 optical multiplexer

113 optical demultiplexer

114 optical fiber

115 output optical fiber

116 output optical connector

117 input optical fiber

118 input optical connector

120a, 120b, 120c, 120d tosa

122 transmitting optical fiber

130 optical receiving sub-module

132 receive optical fiber

133 fiber array

134 photo detector array

136 transimpedance amplifier

200 light emission submodule

202 substrate

204 airtight optical starter

206-1 first end

206-2 second end

208 transmit circuit interface area

210 optical starter drive circuit

212 optical initiator interface region

214-1 first mounting surface

214-2 second mounting surface

216. 218 long axis

222 shim

224 casing

226 cavity

228 feed-through device

230-1 first surface

230-2 second surface

232-1 first part

232-2 second part

234. 236 line

240 laser device

242. 242-1, 242-2, 246 interconnect

244 shim

250. 251, 252, 253 socket

252 temperature control device

254 optical fiber

256 bottom side wall

280 convergence lens

401-1 first side wall

401-2 second side wall

402 first mounting surface

404 temperature control laser device

406 first sub-mount

407 thermoelectric cooler

408 second sub-mount

409 laser sub-mounting piece

410 laser diode

411 array waveguide grating

412 focusing lens

414 ray path

420-1, 420-2, 420-3 and 420-4 holes

430-1 first opening

430-2 second opening

440 weld ring

442 receptacle mount

445 optical isolator

446 lens

447 cannula receiver

448 waveguide

449 Multiplexed optical signal

452 optical fiber column

TX _ D1, TX _ D2, TX _ D3, TX _ D4 drive signals

RX _ D1, RX _ D2, RX _ D3, RX _ D4 electrical data signals

W1, W2, W3 Width

Detailed Description

The detailed features and advantages of the present invention are described in detail in the following embodiments, which are sufficient for those skilled in the art to understand the technical contents of the present invention and to implement the same, and the related objects and advantages of the present invention can be easily understood by those skilled in the art from the disclosure of the present specification, claims and drawings. The following examples further illustrate aspects of the present invention in detail, but are not intended to limit the scope of the present invention in any way.

As described above, some of the tosas can reach optical transmission distances of up to 10km or more. The optical transmitter sub-assembly can be applied to standard applications such as CFP (C form-factor plug), CFP2, CFP4 and QSFP (quad small-factor plug). Generally, such tosas include a hermetically sealed package structure (or simply housing) and an LC receptacle (or other suitable receptacle) for optical coupling. The hermetic package structure may accommodate laser packages such as electro-absorption modulator integrated lasers (EMLs), power monitoring photodiodes (power diodes), thermoelectric coolers (TECs), optical multiplexers (optical multiplexers) such as arrayed waveguide gratings for multiplexed (multiple) multiple frequency wavelengths, electrical interconnects (electrical interconnects) such as printed circuit boards, and optical interconnects (optical interconnects) such as fiber optic columns (fiber stubs). The hermetically sealed structure can include a plurality of cavities (cavities) and these cavities are specifically designed to accommodate these components in a manner that optimizes space constraints and can promote the flow of heat. However, manufacturing the hermetic package structure with the size of the components required to fit the optical actuator increases the manufacturing cost and complexity. Furthermore, for example, thermoelectric coolers may require a large amount of power to be consumed to cool/heat elements in a dense chamber, which ultimately results in a reduction in transmission efficiency.

Accordingly, the present invention generally relates to a tosa having a hermetic housing. The hermetic enclosure includes a laser device (laser arrangement) disposed in the hermetic enclosure for outputting a plurality of channel wavelengths, and a multiplexing device (multiplexing device) disposed outside the hermetic enclosure and being, for example, an arrayed waveguide grating, a filter, or other suitable devices. Specifically, the tosa according to the present invention includes a driver circuit coupled to a hermetically sealed light actuator. The hermetic light starter includes a housing defined by a plurality of sidewalls. The housing defines an airtight chamber to prevent the introduction of contaminants that would otherwise reduce power. The hermetic optical initiator is optically coupled to the external arrayed waveguide grating through an optical receptacle. The optical receptacle can include a waveguide, and the waveguide is implemented, for example, by an optical isolator (optical isolator), a fiber post, and a fiber ferrule portion (fiber ferrule section). Thus, the external awg and associated external optical coupling elements, such as isolators, fiber posts, and fiber ferrule portions, advantageously allow the cavity of the hermetic optical actuator to be of smaller dimensions than other methods of placing the awg and associated elements in the hermetic cavity.

The housing may be referred to herein as hermetically-sealed or hermetically-sealed, and such terms mean that the housing will only be at most about 5 x 10^-8The rate of cubic centimeters per second releases a fill gas (filler gas), wherein the fill gas may comprise an inert gas (inert gas) or a mixture of inert gases. Examples of inert gases are nitrogen, helium, argon, krypton and xenon. The mixture of inert gases is, for example, a nitrogen-helium mixture (nitrogen-helium mix), a neon-helium mixture (neon mix), a krypton-helium mixture (krypton-helium mix) or a xenon-helium mixture (xenon-helium mix).

Here, "channel wavelength" refers to a wavelength associated with an optical channel, and may include a specific wavelength band near a center wavelength. In one example, the channel wavelengths may be defined by an International Telecommunications Union (ITU) standard, such as an ITU-T Dense Wavelength Division Multiplexing (DWDM) grid. The invention is equally applicable to sparse wavelength division multiplexing (CWDM). In a particular example, the channel wavelengths are implemented according to Local Area Network (LAN) Wavelength Division Multiplexing (WDM), which may also be referred to as LWDM. The term "coupled" herein refers to any connection, coupling, interlinking, or similar relationship, and "optically coupled" refers to a coupling relationship in which light is transferred (impart) from one element to another. Such "coupled" devices need not be directly connected to each other and may be separated by intermediate elements or devices capable of manipulating or modifying such signals.

The term "substantially" is used generically herein and refers to a degree of precision within an acceptable error range, wherein an acceptable error range is considered to be and reflects minor real-world variations (minor real-world variations) due to material composition, material imperfections, and/or limitations/singularities in the manufacturing process. This variation may therefore be described as being approximately (largely), but need not fully achieve the described characteristics. To provide a non-limiting example to quantify "substantially," minor variations may cause an error of less than or equal to plus or minus 5% of the specifically described quantity/characteristic, unless otherwise specified.

Referring to the drawings, FIG. 1A shows and describes an optical transceiver 100 according to an embodiment of the invention. In the present embodiment, the optical transceiver 100 uses four different channel wavelengths (λ)₁、λ₂、λ₃、λ₄) Four channels of signals are transmitted and received and can have a transmission speed of at least about 25Gbps/s per channel. In one example, the channel wavelength λ₁、λ₂、λ₃、λ₄Can be 1270 nanometer (nm), 1290nm, 1310nm and 1330nm, respectively. Other channel wavelengths, including those associated with lan wavelength division multiplexing, are also within the scope of the present invention. The optical transceiver 100 can also have a transmission distance of 2 kilometers (km) to about 10 km. The optical transceiver 100 may be used, for example, for network data center applications (internet data centers) or Fiber To The Home (FTTH) applications.

Although the following examples and embodiments present and describe a four-channel (4-channel) optical transceiver, the present invention is not limited thereto. For example, the present invention is equally applicable to 2, 6 or 8 channel configurations.

The optical transceiver 100 disclosed in this embodiment includes a plurality of transmitter optical sub-modules (TOSAs) 120a, 120b, 120c, and 120d and a multi-channel receiver optical sub-module (ROSA) 130, wherein the TOSAs 120a, 120b, 120c, and 120d are configured to transmit optical signals at different channel wavelengths, and the multi-channel ROSA 130 is configured to receive optical signals at different channel wavelengths. The tosas 120a, 120b, 120c, 120d and the rosas 130 are located in the transceiver housing 102.

The transmitter connection circuit 104 and the receiver connection circuit 108 provide electrical connections to the tosas 120a, 120b, 120c, 120d and the rosas 130 of multiple channels, respectively, in the housing 102. The transmitter connecting circuit 104 is electrically connected to the electronic components (e.g., laser, screen photo diode, etc.) in each of the tosas 120a, 120b, 120c, 120d, and the receiver connecting circuit 108 is electrically connected to the electronic components (e.g., photo diode, transimpedance amplifier, etc.) in the rosa 130. The transmit connection circuitry 104 and the receive connection circuitry 108 may be flexible printed circuits that include at least conductive paths to provide electrical connections, and may also include additional circuitry.

As described in detail below, each of the tosas 120a, 120b, 120c, 120d may be implemented as a tosa 200. Each tosa may be electrically coupled to a conductive path on the TX connection circuit 104, and may be configured to receive a driving signal (e.g., TX _ D1, TX _ D2, TX _ D3, TX _ D4) and transmit a channel wavelength onto an optical fiber of the transmitting fiber 122.

The multi-fiber push on (MPO) connector 110 provides optical connections to the tosas 120a, 120b, 120c, 120d and the tosas 130 in the housing 102. The MPO connector 110 is optically coupled to the tosas 120a, 120b, 120c, 120d and the multi-channel tosa 130 through the transmitting fibers 122 and the receiving fibers 132, respectively. The MPO connector 110 is adapted to couple to a mating MPO connector 112 such that the transmit and receive fibers 122, 132 of the optical transceiver 100 are optically coupled to the external fibers 114.

Next, the multiple-channel rosa 130 of the embodiment shown in fig. 1A includes a photodetector (photodetector) array 134, wherein the photodetector array 134 includes, for example, photodiodes optically coupled to an optical fiber array 133, and the optical fiber array 133 is formed by the ends of the receiving optical fibers 132. The multi-channel rosa 130 also includes a multi-channel transimpedance amplifier (transimpedance amplifier)136, and the multi-channel transimpedance amplifier 136 is electrically connected to the photodetector array 134. The photodetector array 134 and the transimpedance amplifier 136 detect the optical signals received from the fiber array 133 and convert the optical signals into electrical data signals RX _ D1, RX _ D2, RX _ D3, RX _ D4, wherein the electrical data signals are output through the receive connection circuitry 108. Other embodiments of the rosa may be used in the optical transceiver 100 to receive and detect one or more optical signals.

The optical transceiver 100 provided in this embodiment does not include an optical multiplexer (multiplexer) or demultiplexer (demultiplexer). The optical signals may be multiplexed or demultiplexed at the optical transceiver 100.

Referring to fig. 1B, another embodiment of the optical transceiver 100' includes the optical actuators (e.g., the tosas 120a, 120B, 120c, 120d and the rosa 130) as described above, and further includes an optical multiplexer 111 and an optical demultiplexer 113. Both the optical multiplexer 111 and the optical demultiplexer 113 may comprise an Arrayed Waveguide Grating (AWG). The optical multiplexer 111 is optically coupled to the transmission optical fiber 122, and the optical demultiplexer 113 is optically coupled to the reception optical fiber 132. Optical multiplexer 111 multiplexes the optical signal being transmitted through transmit fiber 122 to provide a multiplexed optical signal to output fiber 115. The optical multiplexer 113 demultiplexes the optical signal received and multiplexed by the input fiber 117 to thereby provide the received optical signal to the receiving fiber 132. Output optical fiber 115 and input optical fiber 117 are coupled to output optical connector 116 and input optical connector 118, respectively.

The optical transceiver 100' provided in this embodiment includes 4 channels and may be used for sparse wavelength division multiplexing, but may include other numbers of channels. The optical transceiver 100' provided by the present embodiment may also have a transmission rate of at least about 25Gbps per channel and a transmission distance of at least about 2km to 10km, and may be used for network data center applications or fiber to the home applications.

Please refer to fig. 2A-2B, which illustrate an exemplary tosa 200 according to an embodiment of the present invention. The tosa 200 may be implemented as an tosa device in the optical transceivers 100 and 100'. As shown in the drawings, the TOSA 200 includes a substrate 202 and an airtight light initiator 204, wherein the airtight light initiator 204 is coupled to one end of the substrate 202. Specifically, the substrate 202 includes a first end 206-1, and the first end 206-1 extends along the longitudinal axis 216 to a second end 206-2. The substrate may comprise a Printed Circuit Board (PCB) formed of silicon or any other material capable of being coupled/mounted to an electronic component. The substrate 202 includes at least two mounting surfaces for mounting components, such as a first mounting surface 214-1 and a second mounting surface 214-2 oppositely disposed in an opposing arrangement (alignment)/layout (configuration).

The substrate 202 includes a transmit circuit (TX) interface area 208, an optical initiator interface area 212, and an optical initiator driver circuit 210, wherein the transmit circuit interface area 208 is adjacent to the first end 206-1, the optical initiator interface area 212 is adjacent to the second end 206-2 of the substrate, and the optical initiator driver circuit 210 is disposed between the transmit circuit interface area 208 and the optical initiator interface area 212. The transmit circuit interface area 208 may include a plurality of terminals/pads (pads) for electrically coupling with transmit connection circuitry, such as transmit connection circuitry 104. The transmit circuit interface area 208 may thus receive signals, such as power signals or other signals such as Radio Frequency (RF), from the associated transmit connection circuit when coupled thereto. Optical initiator interface area 212 also includes pads 222 (or terminals) for electrically coupling with hermetic optical initiator 204.

Optical initiator drive circuit 210 may include power conversion circuitry and other chips/devices suitable for driving an optical initiator, such as hermetic optical initiator 204. The optical actuator driving circuit 210 may be disposed on one or more mounting surfaces of the substrate 202. For example, as shown in FIG. 2A and FIG. 2B, the optical driving circuit is disposed on the first mounting surface 214-1 and the second mounting surface 214-2. This double-sided arrangement allows Radio Frequency (RF) and Direct Current (DC) lines (trace) to be independent of each other, which is advantageous in minimizing or reducing their electrical interference with each other. However, the invention is not limited thereto, and the optical driving circuit may be disposed on only one side of the substrate 202 according to the conventional configuration. The optical initiator driver circuit 210 may be electrically coupled to the transmitter circuit interface area 208, and more specifically to a plurality of terminals/pads, via wires. Similarly, the optical initiator driver circuit 210 may be electrically coupled to pads/terminals of the optical initiator interface region 212 through wires, which will be described in detail below.

Hermetic light initiator 204 includes a hermetic housing 224 or housing 224 defined by a plurality of sidewalls. The housing 224 may include an elongated axis 218, and the elongated axis 218 substantially passes through the elongated axis 216 of the substrate 202. The housing 224 may comprise, for example, metal, plastic, ceramic, or any other suitable material. The housing 224 may be a modular structure or a unitary structure.

The housing 224 further defines a cavity 226 for the laser (as shown in fig. 3), and the cavity 226 for the laser can be filled with an inert gas to form an inert gas ring (inert atmosphere). In one embodiment, the inert gas sealed in the hermetic container comprises nitrogen, and preferably comprises nitrogen at 1 atmosphere. The inert gas may be formed from nitrogen, helium, argon, krypton, xenon, or mixtures thereof, wherein the mixture includes a nitrogen-helium mixture, a neon-helium mixture, a krypton-helium mixture, or a xenon-helium mixture. The inert gas or gas mixture included in the hermetic container may be selected with a specific refractive index or other optical properties. These gases may also be selected based on their ability to promote thermal insulation. For example, helium, which is considered to promote heat transfer, may be used alone or in combination with the above-mentioned gases. In any case, airtight and airtight are used interchangeably and refer to a housing only at most about 5 × 10^-8The fill gas is released at a rate of cubic centimeters per second.

As shown in the figures, the housing 224 may abut or abut (abut) (e.g., be directly coupled to) the second end 206-2 of the substrate 202 and extend from the second end 206-2. This may also be referred to as an end-to-end (end-to-end) connection between the housing 224 and the substrate 202. The housing 224 may be securely attached to the substrate by adhesive or other suitable means, such as screws, rivets, friction-fit (friction-fit), tongue and groove mating, or any combination thereof. However, the housing 224 may not be directly coupled to the second end 206-2 of the substrate 202, but may be indirectly coupled to the second end 206-2 of the substrate 202 through an intermediate device/structure.

As shown in fig. 2A and 2B, alternatively, or in addition to adhesive or other attachment means, the housing 224 may be securely attached to the substrate 202 according to electrical interconnect means (or simply interconnect means) soldered or coupled between the substrate 202 and the housing 224. For example, a first type of interconnect device is shown generally at 242 and at 242-1 and 242-2, respectively, and may be coupled to the substrate 202 via respective pads 222. The first type of interconnect device 242 may be substantially similar in size and type, although other embodiments are within the intended scope of the invention. For example, the respective interconnect devices 242 may be substantially similar in size and may each comprise copper, aluminum, iron, or other suitable conductive metal or alloy. In other embodiments, the interconnect device 242-1 and the interconnect device 242-2 may comprise different metal materials and have different dimensions. In a particular exemplary embodiment, the interconnect 242 comprises Direct Current (DC) bus interconnects.

As shown in the figures, the interconnect device 242-1 may be coupled to the first mounting surface 214-1 of the substrate 202, and the interconnect device 242-2 may be disposed on the second mounting surface 214-2 of the substrate 202 opposite the interconnect device 242-1. This relative configuration/arrangement may increase the structural stability of the interface between the housing 224 and the substrate 202 relative to coupling the interconnect device on only one side of the substrate 202. In this embodiment, each first interconnect 242-1 may be disposed in a coextensive manner with a corresponding second interconnect 242-2, although in other embodiments the interconnects may be disposed in a staggered manner rather than coextensive. In some embodiments, the interconnect device 242 may be coupled to only one side to provide electrical communication between the substrate 202 and the housing 224, and the invention should not be limited thereto.

In any event, the interconnect 242 may suitably be a rigid body that prevents or reduces rotation of the housing 224 relative to the base plate 202. For example, more than 50% of the real estate (substitional port) of the bottom surface of each interconnect 242 may be coupled to the pad 222 of the substrate 202. This allows a relatively large surface area of the interconnect device 242 to contact the substrate 202, thereby allowing additional soldering. Additional soldering may further increase the strength of the structural support and securely maintain the position of the housing 224 relative to the substrate 202. Thus, in some embodiments, the ratio of the surface area of each interconnect device 242 coupled to the substrate 202 relative to the housing 224 may be 2:1, 3:1, 4:1, 6:1, or any ratio.

In one embodiment, each interconnect 242 may form a substantially continuous electrical conductor (electrical conductor) when electrically coupled to the associated pad 222 in the substrate 202 and the pad 244 of the housing 224, wherein each interconnect 242 is electrically coupled to the substrate 202, such as by soldering or otherwise. The continuous electrical conductor may be linear and, for example, have no bent profile. Although the interconnection device 242-2 may be used to carry a dc signal, the substrate 202 and associated pads in the housing 224 need not be electrically coupled to the optical actuator driver circuit 210 and the laser device 240, wherein the laser device 240 may also be referred to as a laser delivery device or as a laser package, as shown in fig. 3. Conversely, the interconnect device 242-2 may be electrically isolated and may serve only to provide structural support (e.g., prevent rotation) and/or grounding between the substrate 202 and the housing 224. Additionally, one or more of interconnects 242-2 may be electrically isolated, while other interconnects 242-2 may be used to provide a DC signal between substrate 202 and hermetic optical initiator 204.

Also, a second type of interconnect device 246 may electrically couple substrate 202 to hermetic optical initiator 204 to provide radio frequency signal transmission (signaling). The second type of interconnect device 246 may include wire bonds (bonding) as shown in the figures, but other types of interconnect devices may be used. As shown in the figures, the embodiment of fig. 2B and 2C includes a plurality of second type of interconnection devices 246. The wire bonds may be particularly suitable for transmitting high frequency radio frequency signals. However, the bonding wires can be easily damaged, for example, due to movement between the substrate 202 and the housing 224. In one embodiment, the first type of interconnect device 242 may introduce rigidity and a secure connection between the substrate 202 and the housing 224, thereby preventing or reducing the chance of damage.

Fig. 3 presents a cross-sectional view of housing 224 in accordance with an embodiment of the present invention. As shown in the figures, the housing 224 includes a plurality of sidewalls that define a cavity 226. The cavity 226 includes a laser device 240 disposed therein. The laser device 240 may be used to launch the associated channel wavelength into an optical fiber and/or other waveguide disposed in the receptacle 250 (or connector), where the light is, for example, one of the optical fibers 254 (see fig. 2B). It is noted that the optical fiber 254 can be implemented as the transmit fiber 122 in fig. 1A and 1B. Focusing lenses (Focusing lenses), such as a collection optic 280, may be disposed in the cavity 226 and aligned with the associated laser package structure to emit light from the associated laser package structure into the optical fibers or waveguides of the receptacle 250. The cavity 226 may also include a temperature control device 252 in thermal communication with the laser device 240. Temperature control device 252 may include a thermoelectric cooler or other suitable device. The temperature control device 252 may also be in thermal communication with the bottom sidewall 256 to enable heat transfer. Accordingly, the temperature control device 252 may facilitate heat dissipation through a metal housing (or other housing) in which the housing 224 may be disposed.

The cavity 226 may be formed at least in part by a feed-through or passthrough device 228. Feedthru device 228 may comprise, for example, a suitable rigid non-metallic material, such as an inorganic material, for example, silicon oxide (crystalline oxide), silicon nitride, or carbide materials, and are commonly referred to as ceramics. Elements such as carbon or silicon may also be referred to as ceramics and are within the scope of the present invention. First portion 232-1 of feedthrough 228 may extend at least partially into the cavity and second portion 232-2 may extend from cavity 226.

Feedthru device 228 may be defined by at least a first surface 230-1 (which may also be referred to as a first mounting surface) and a second surface 230-2 (which may also be referred to as a second mounting surface), with the opposing arrangement/configuration of second surface 230-2 being oppositely disposed to first surface 230-1. The first surface 230-1 and the second surface 230-2 may include circuitry disposed or patterned thereon. For example, the first surface 230-1 may include a line 234 (or referred to as a dc line) disposed thereon, and the line 234 is used for transmitting a dc signal. On the other hand, the second surface 230-2 may include a line 236 (or referred to as an rf line) disposed thereon, and the line 236 is used for transmitting rf signals. Feed-through device 228 may have a width W1 (or thickness) and a width W1 of between 0.1 and 2 millimeters (mm), although other dimensions are within the scope of the present disclosure. Feedthru device 228 has a width W1 to prevent or mitigate electrical interference between the dc signal and the rf signal carried by lines 234 and 236, respectively. The width W1 of the feedthrough device 228 may be equal to the width W2 of the substrate 202. However, the width W1 and the width W2 may be different, and the width W2 may be greater or less than the width W1. As further shown in the figures, when substrate 202 and feedthrough device 228 are coupled together, first and second mounting faces 214-1 and 214-2 of substrate 202 may extend parallel to first and second surfaces 230-1 and 230-2 of feedthrough device 228 and may be substantially coplanar with first and second surfaces 230-1 and 230-2.

Also, a first end of the line 234 may be electrically coupled to the substrate 202, and in particular, to the optical actuator driving circuit 210 through various interconnection devices, such as the interconnection device 242-1 of the first type. As shown in the drawings, a second end of the trace 234 on the first surface 230-1 of the feedthrough device 228 may then be wire bonded or otherwise electrically coupled to a laser device 240 in a suitable manner. Each laser device 240 may comprise, for example, a laser diode and a screen photodiode, and may be used to emit the associated channel wavelength. Similarly, a first end of the line 234 is electrically coupled to the optical actuator driving circuit 210 through each interconnection device, such as a second type interconnection device 242-2, and a second end is electrically coupled to the laser device 240 through a bonding wire or other suitable method.

Fig. 4-5 show additional configurations of tosa 200 according to the present invention. As shown in the drawings, the housing 224 is defined by a plurality of sidewalls, and the plurality of sidewalls at least includes a first sidewall 401-1 and a second sidewall 401-2. As described above, the housing 224 may comprise metal, and thus the sidewalls defining the housing 224 may be comprised of metal. The metal is particularly adapted to transfer heat, and the sidewalls may be adapted to communicate/transfer heat from the optical elements in the cavity 226. For example, the side wall may also be in communication with the side wall of the optical transceiver housing, and may also communicate and dissipate heat through the optical transceiver housing.

The first and second sidewalls 401-1 and 401-2 may be defined by at least one surface extending substantially parallel to the first and second mounting surfaces 214-1 and 214-2 (as shown in fig. 2A and 2B), wherein the first and second mounting surfaces 214-1 and 214-2 define the first and second surfaces of the substrate 202. The first sidewall 401-1 and the second sidewall 401-2 may be disposed opposite to each other in an opposite arrangement. The first sidewall 401-1 and the second sidewall 401-2 may at least partially define the cavity 226.

The first sidewall 401-1 has at least one first mounting surface 402. The first mounting surface 402 may be substantially flat, but the invention is not limited thereto. As shown in the figure, the cavity 226 includes a temperature controlled laser device 404 disposed on the first mounting surface 402. In particular, the temperature controlled laser device comprises a first sub-mount 406 for a thermo-electric cooler, a thermo-electric cooler 407, a second sub-mount 408 for a thermo-electric cooler, a laser sub-mount 409, a plurality of laser diodes 410 and a plurality of focusing lenses 412. The first sub-mount 406 may be disposed on the first mounting surface 402 and may be used to support a stack of elements as shown in the figures. A plurality of thermoelectric coolers 407 may then be disposed on the first sub-mount 406. Second sub-mount 408 may then be disposed on a top surface of thermoelectric cooler 407 such that the top surface of thermoelectric cooler 407 is directly coupled to a bottom surface of second sub-mount 408. In some embodiments, thermoelectric cooler 407 may not need to be directly coupled to second sub-mount 408, and the invention is not limited thereto. Thermoelectric cooler 407 may thus support thermoelectric cooler 407 and be in thermal communication between second submount 408 and first submount 406.

The second or top surface of the second sub-mount 408 may have mounting (or support) surfaces for the laser sub-mount 409 and the focusing lens 412 (which may alternatively be referred to as a collimating lens). The laser sub-mount 409 includes at least one mounting surface for coupling to the laser diode 410 and associated circuitry. As shown in fig. 3, the laser sub-mount 409 may be coupled to multiple laser devices, but in some embodiments there may be a separate laser sub-mount for each laser diode.

Also, the laser sub-mount 409 may have a width W3 to support and align each laser diode 410 such that laser light energy is emitted substantially along the ray path 414 to the center of each associated focusing lens 412. The cavity 226 may further include a lens 446 disposed along the ray path 414. The lens 446 may be angled at about 2 to 8 degrees from the light path 414 to reduce back reflection (back reflection) and ensure optimal coupling efficiency.

As best shown in FIG. 6, the housing 224 may further include a sidewall, and the sidewall includes a plurality of openings 420-1, 420-2, 420-3, 420-4. Each of the openings 420-1, 420-2, 420-3, 420-4 may have a different radius. For example, the opening 420-1 includes a first opening 430-1 coupled to a second opening 430-2. The first opening 430-1 may be adjacent to the associated laser diode and focusing lens, and the second opening 430-2 may be adjacent to the receptacle 250. The radius of the first aperture 430-1 may be greater than the radius of the second aperture 430-2. As described above, each opening 420-1, 420-2, 420-3, 420-4 enables an associated channel wavelength to be emitted from the cavity 226.

Also, each of the fiber coupling receptacles 250, 251, 252, 253 is coupled to the housing 224 with a welding ring (welding ring)440 and a receptacle mount 442. Each receptacle 250, 251, 252, 253 may further include an optical pathway/waveguide that includes an optical isolator 445, a fiber post 452, and a ferrule (ferrule) receptacle 447 (or fiber receptacle), although other embodiments are within the scope of the present invention.

As shown in fig. 4 and 5, each receptacle 250, 251, 252, 253 enables an intermediate waveguide, such as waveguide 448, to be optically coupled to the arrayed waveguide grating 411. The arrayed waveguide grating 411 may then multiplex the channel wavelengths received through the respective intermediate waveguides and output a multiplexed optical signal 449, where the arrayed waveguide grating 411 receives the channel wavelengths through the intermediate waveguides, for example, through the apertures 420-1, 420-2, 420-3, 420-4. The multiplexed optical signal 449 may then be transmitted over an output fiber, such as output fiber 115 in fig. 1B.

As shown in the figure, each of the receptacles 250, 251, 252, 253 is extended by an optical isolator 445 and a fiber post 452 such that the waveguide 448 and the arrayed waveguide grating 411 are disposed outside the cavity 226. It should be noted that although the figure shows the arrayed waveguide grating 411, other multiplexing devices such as filters can be used and are within the scope of the present invention. Thus, the number of components in the cavity 226 is reduced, such that the cavity 226 may be hermetically sealed and have dimensions that reduce manufacturing complexity and cost. This further enables external optical components to be coupled/mounted to the housing 224 before or after the housing 224 is hermetically sealed and has better operability (serviceability) because components external to the hermetically sealed cavity 226 can be more easily replaced/repaired than components located within the hermetically sealed cavity 226. In addition, the size and/or number of thermoelectric coolers may be reduced or decreased as the size of cavity 226 is decreased, which may reduce the number of elements that need to be heated/cooled and reduce the area surrounding these elements. The use of a relatively small size thermoelectric cooler and/or a small number of collating elements may reduce heating/cooling related power consumption and further reduce overall cost and manufacturing complexity.

According to one aspect of the invention, an tosa is disclosed. The tosa includes a hermetically sealed optical initiator and a multiplexer. The airtight optical initiator has a housing and a plurality of laser devices. The shell defines an airtight cavity. The laser device is disposed in the hermetically sealed cavity and is configured to emit a plurality of associated channel wavelengths. The multiplexer is disposed outside the hermetic chamber and optically coupled to the hermetic optical actuator to receive the associated channel wavelength and output a multi-tap signal.

According to another aspect of the invention, an optical transceiver is disclosed. The optical transceiver comprises a shell, an optical transmit sub-module and an optical receive sub-module. The transmitter optical subassembly is disposed in the housing and includes an airtight optical actuator and an array waveguide grating. The airtight optical initiator has a housing and at least one laser device. The shell defines an airtight cavity. The laser device is arranged in the airtight cavity. The arrayed waveguide grating is arranged outside the airtight cavity and is optically coupled to the airtight optical initiator so as to receive a plurality of relevant channel wavelengths and output a multi-wavelength signal. The light receiving submodule is arranged on the shell.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.