阅读说明：本技术 具有集成背侧透镜的光二极管阵列以及实施其之多频道收发器模组 (Photodiode array with integrated backside lens and multichannel transceiver module implementing the same ) 是由 王修哲 马伦特斯·艾尔西 李秦 于 2019-11-27 设计创作，主要内容包括：本申请公开了一种包括多频板上光接收次模组配置的光收发器,且多频板上光接收次模组配置包括设置于相同基板的光学解多工器及光二极管阵列。光学解多工器例如为阵列波导光栅。光二极管阵列可光学对准于光学解多工器的输出端口,并用于侦测频道波长及输出正比电性信号给诸如跨阻抗放大器的放大电路。各个光二极管能包括集成透镜,且集成透镜用于增加光学解多工器及光感测区域之间的校准公差,而使得使用诸如芯片接合的相对较不精准的接合技术时仍能保持标称的光学功率。(The application discloses an optical transceiver including a multi-band board optical receiving sub-module configuration, and the multi-band board optical receiving sub-module configuration includes an optical demultiplexer and a photodiode array disposed on the same substrate. The optical demultiplexer is, for example, an arrayed waveguide grating. The photodiode array may be optically aligned with an output port of the optical demultiplexer and used to detect channel wavelength and output a proportional electrical signal to an amplification circuit, such as a transimpedance amplifier. Each photodiode can include an integrated lens for increasing alignment tolerances between the optical demultiplexer and the light sensing region, while maintaining nominal optical power using relatively imprecise bonding techniques, such as chip bonding.)

1. An optical transceiver module, comprising:

the base plate is provided with a first end, the first end extends to a second end, and the base plate is provided with at least one first mounting surface; and

an on-board light receiving sub-module arrangement, said on-board light receiving sub-module arrangement comprising:

a photodiode array mounted on the first mounting surface of the substrate;

an optical demultiplexer mounted on the first mounting surface of the substrate, the optical demultiplexer having an optical output port aligned with and optically coupled to the photodiode array; and

wherein each of the plurality of photodiodes in the photodiode array includes an integrated lens to increase alignment tolerances between the optical demultiplexer and the light sensing area of each of the photodiodes in the photodiode array.

2. The optical transceiver module of claim 1 wherein the optical demultiplexer is configured to receive a signal having a plurality of channel wavelengths and output at least five different channel wavelengths.

3. The optical transceiver module of claim 1, wherein the photodiode array is mounted to the first mounting surface by a photodiode submount.

4. The optical transceiver module of claim 3, wherein the photodiode base is configured to couple to more than four photodiodes, and the photodiode base is a monolithic structure.

5. The optical transceiver module of claim 1, further comprising a first amplifier circuit and a second amplifier circuit mounted to the first mounting surface of the substrate and electrically coupled to the photodiode array.

6. The optical transceiver module of claim 1, wherein the optical demultiplexer comprises an arrayed waveguide grating.

7. The optical transceiver module of claim 1, wherein each of the photodiodes in the photodiode array provides increased calibration tolerance based on a position of the integrated lens.

8. The optical transceiver module of claim 1, wherein the substrate comprises a printed circuit board assembly.

9. An optical transceiver, characterized in that the optical transceiver comprises:

a housing defining a cavity for receiving the optical transceiver module; and

an optical transceiver module disposed at least partially within the cavity of the housing, the optical transceiver module comprising:

the base plate is provided with a first end, the first end extends to a second end, and the base plate is provided with at least one first mounting surface;

an on-board light receiving sub-module arrangement, said on-board light receiving sub-module arrangement comprising:

a photodiode array mounted on the first mounting surface of the substrate;

an arrayed waveguide grating mounted to the first mounting face of the substrate, the arrayed waveguide grating having an optical output port aligned with and optically coupled to the photodiode array; and

wherein each of a plurality of photodiodes in the photodiode array includes an integrated lens to increase alignment tolerances between the arrayed waveguide grating and a light sensing region of each of the photodiodes in the photodiode array; and

a light emitting sub-module arrangement mounted to the substrate.

10. The optical transceiver of claim 9 wherein the arrayed waveguide grating is configured to receive a signal having a plurality of channel wavelengths and output at least five different channel wavelengths.

11. The optical transceiver of claim 9, wherein the photodiode array is mounted to the first mounting surface by a photodiode submount.

12. The optical transceiver of claim 11, wherein the photodiode submount is to couple to more than four of the photodiodes.

13. The optical transceiver of claim 9, further comprising a first amplification circuit and a second amplification circuit mounted to the first mounting surface of the substrate and electrically coupled to the photodiode array.

14. The optical transceiver of claim 9, wherein the arrayed waveguide grating includes a base portion coupling the arrayed waveguide grating to the first mounting surface and a body defining at least one optical path for splitting channel wavelengths and optically coupling the arrayed waveguide grating to the photodiode array, the at least one optical path not extending through the base portion.

15. The optical transceiver of claim 9, wherein the increased calibration tolerance is a function of a position of each of the integrated lenses relative to the light sensing region.

16. A photodiode device, for use in an optical subassembly, the photodiode device comprising:

a base having at least a first side and a second side opposite to each other;

a plurality of electrical connection portions disposed on the first side;

a light sensing area; and

an integrated lens adjacent to the second side and above the light sensing area to increase alignment tolerances between an optical demultiplexer and the light sensing area of the photodiode device.

17. The photodiode apparatus of claim 16, wherein the integrated circuit at least doubles the calibration tolerance.

Technical Field

The present invention relates to optical communication, and more particularly, to a photodiode array having a plurality of photodiode chips, wherein each of the photodiode chips has an integrated lens to enlarge a light sensing area thereof, thereby increasing tolerance during an alignment process.

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 transmitter optical sub-modules (TOSAs) for transmitting optical signals and one or more receiver optical sub-modules (ROSAs) for receiving optical signals. In general, the tosa includes one or more lasers for emitting signals at one or more channel wavelengths and associated circuitry for driving the lasers. Generally, the optical receive sub-module includes an optical demultiplexer and one or more lenses. Some existing optical transceiver modules support up to four channels for transmitting and receiving optical signals. Significant (significant) technical challenges inhibit the design and manufacture of optical transceiver modules with more than four channels.

Disclosure of Invention

According to an embodiment of the invention, an optical transceiver module is disclosed. The optical transceiver module includes a substrate and an on-board optical transceiver sub-module arrangement. The substrate has a first end extending to a second end. The substrate is provided with at least one first mounting surface. The on-board optical receive sub-module arrangement includes an array of photodiodes and an optical demultiplexer. The photodiode array is mounted on the first mounting surface of the substrate. The optical demultiplexer is mounted on the first mounting surface of the substrate. The optical demultiplexer has an optical output port. The optical output port is aligned with and optically coupled to the photodiode array. Each of the plurality of photodiodes in the photodiode array includes an integrated lens to increase alignment tolerances between the optical demultiplexer and the light sensing area of each of the photodiodes in the photodiode array.

Drawings

These and other features and advantages will be better understood from a reading of the following detailed description and drawings. In the drawings:

fig. 1 is a block diagram of a multi-channel optical transceiver according to an embodiment of the present invention;

FIG. 2 is a perspective view of a multi-channel optical transceiver module according to the present invention;

FIG. 3 is a side view of the multi-channel optical transceiver module of FIG. 2 in accordance with one embodiment of the present invention;

FIG. 4 is a perspective view of an on-board optical receive sub-module configuration of the multi-channel optical transceiver module of FIG. 2 in accordance with one embodiment of the present invention;

FIG. 5 is a side view of the on-board light receiving sub-module arrangement of FIG. 4 according to one embodiment;

FIG. 6 is another perspective view of the on-board light receiving sub-module arrangement of FIG. 4 according to one embodiment;

FIGS. 7A and 7B present an exemplary array of photodiodes suitable for use in the on-board light-receiving sub-module configuration of FIG. 4, according to one embodiment;

fig. 8A-8C collectively present photodiodes with integrated lenses suitable for use in the photodiode arrays of fig. 7A and 7B, according to an embodiment.

Description of reference numerals:

optical transceiver module 100

Optical transceiver substrate 102

Transceiver housing 103

Light emitting sub-module arrangement 104

Transmission connection circuit 106

Optical receive sub-module arrangement 108

Fiber optic receptacle 110

Receiving connection circuit 112

Laser diode device 114

Lines 116, 119

Arrayed waveguide grating 118

Receiving optical fiber 123

Optical demultiplexer 124

Launch fiber 125

Photosensor array 126

First transimpedance amplifier 128-1

Second transimpedance amplifier 128-2

Connector pad 214

Driving electrical signals TX _ D1 through TX _ D8

Electrical signals RX _ D1-RX _ D8

Optical transceiver module 200

Substrate 202

First end 203

Second end 204

Light emission sub-module arrangement 206

Optical receive sub-module arrangement 208

Fiber optic receptacle 210

Intermediate waveguide 211

Photodiode arrangement 223

Optical demultiplexer 224

Input port 225

Photodiode array 226

Output port 227

First transimpedance amplifier 228-1

Second transimpedance amplifier 228-2

First mounting surface 245

Second mounting surface 246

Major axis 250

Light path 255

First photodiode submount 256-1

Second photodiode submount 256-2

Photodiode base 702

Mounting face 704

Contact portion 708

Orientation marker 710

Cathode contact 712

Anode contact 714

Partition 720

Integrated lens 802

Cathode contact 804

Anode contact 806

Optical bonding pad 808

Detailed Description

As described above, significant challenges limit the increased channel allocation of optical transceiver modules beyond four channels. One such limitation includes the availability of transimpedance amplifier (TIA) chips with more than four channels for output/input. Thus, for example, for a design operating with eight channels, it is necessary to include at least two Arrayed Waveguide Gratings (AWGs) of four channels, at least two 1 × 4 photo sensor arrays, and two transimpedance amplifier four-channel chips for receiving and amplifying optical signals. The increased number of components such as arrayed waveguide gratings and transimpedance amplifiers increases the cost per unit and introduces a (non-visual) optical alignment problem that ultimately reduces yield and cannot be easily addressed. Taking the example of a photodiode coupled to a photo sensing area having 20 microns (microns), die bonding can have a tolerance of + -10 microns, while a demultiplexer (demultiplexer) has only a relatively small tolerance of + -7 microns. This difference makes it difficult to achieve uniform optical alignment between the photodiodes and the demultiplexer, thereby reducing yield. In addition, the photodiode must be disposed relatively close to the transimpedance amplifier to reduce an interconnection delay such as time of flight (ToF). This proximity may risk damage to vulnerable components such as wire bonds (bond pads) when the spacing between adjacent transimpedance amplifiers and respective photodiodes is several microns during fabrication.

The present invention generally relates to an optical transceiver including a multichannel board optical receive sub-module arrangement capable of receiving more than four channel wavelengths. In one embodiment, the on-board optical sub-module includes at least one eight-channel optical demultiplexer, such as an arrayed waveguide grating, and a 1x8 array of photodiodes disposed on the same substrate. The array of photodiodes may be optically aligned with the output port of the optical demultiplexer and used to detect channel wavelength and output a proportional electrical signal to associated amplification circuitry, such as a transimpedance amplifier. Each photodiode can include an integrated lens (integrated lens) for increasing alignment tolerances between the demultiplexer and the photo-sensing region of each photodiode, while maintaining nominal optical power using relatively imprecise bonding techniques, such as chip bonding. This may advantageously enable, for example, the arrayed waveguide grating and the photodiode to be coupled to the same substrate despite differences in tolerances.

In this context, "on-board" used to form the optical receive sub-module arrangement includes ways to directly or indirectly couple the optical receive sub-module elements to a common (common) substrate. The elements of the LRM configuration may be coupled to the same or different surfaces on the same substrate. Similarly, the light emitting sub-module elements may be coupled to the same or different surfaces of the substrate. In some cases, the substrate may include a plurality of blocks (pieces)/segments (segments), and the present invention is not limited to the use of a single substrate.

Herein, "channel wavelength" refers to a wavelength associated with an optical channel, and may include a specific wavelength band around a center wavelength. In one example, the channel wavelengths may be defined by an International Telecommunications (ITU) standard, such as an ITU-T high Density Wavelength Division Multiplexing (DWDM) grid. The present invention is equally applicable to low density wavelength division multiplexing (CWDM). In a specific example, the channel wavelength is implemented according to Local Area Network (LAN) Wavelength Division Multiplexing (WDM), and the area network wavelength division multiplexing 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 result in an error of less than or equal to ± 5% of the specifically described quantity/characteristic, unless otherwise specified.

Referring to the drawings, FIG. 1 shows an optical transceiver module 100 according to an embodiment of the invention. For clarity of presentation and ease of illustration, and not by way of limitation, the optical transceiver module 100 is presented in a highly simplified manner. In the present embodiment, the optical transceiver module 100 transmits and receives signals of eight channels using eight different channel wavelengths (λ 1 to λ 8), and each channel can have a transmission speed of at least about 25 Gbps. In one example, the channel wavelengths λ 1, λ 2, λ 3, λ 4, λ 5, λ 6, λ 7, λ 8 may be 1273 nanometers (nm), 1277nm, 1282nm, 1286nm, 1295nm, 1300nm, 1304nm, and 1309nm, respectively. Other channel wavelengths, including those associated with wavelength division multiplexing for local area networks, are also within the scope of the present invention. The optical transceiver module 100 may also have a transmission distance of 2 kilometers (km) to at least about 10 km. The optical transceiver module 100 may be used, for example, for network data center applications (internet data centers) or Fiber To The Home (FTTH) applications.

In one embodiment, the optical transceiver module 100 is disposed in a transceiver housing 103. Depending on the desired configuration, the transceiver housing 103 can have one or more cavities, such as a cage or slot, for receiving one or more optical transceiver modules. In one embodiment, the optical transceiver module 100 is configured as a pluggable module (pluggable module).

The optical transceiver module 100 may include a number of components that support the operation of the transceiver. The optical transceiver module 100 may include an optical transceiver substrate 102, an optical transmit sub-module arrangement 104, transmit connection circuitry 106, a multi-channel optical receive sub-module arrangement 108, a fiber receptacle 110, and receive connection circuitry 112. The transmitter sub-module arrangement 104 is configured to transmit optical signals of different channel wavelengths. The optical receive sub-module arrangement 108 is configured to receive optical signals of different channel wavelengths. The fiber receptacle 110 is used to receive and calibrate the optical receive sub-module arrangement 108 and a fiber connector, such as a ferrule.

The optical transceiver substrate 102 may be fabricated from a multi-layer printed circuit board, but other types of substrates may be used and are within the scope of the present invention. In one embodiment, the substrate comprises a printed circuit board assembly. The optical transceiver substrate 102 includes traces, connector pads, and other circuitry to support operation of the transceiver. The optical transceiver substrate 102 may include a tosa connector pad 214 (e.g., see fig. 2), wherein the tosa connector pad 214 enables the tosa arrangement 104 to be mounted and electrically coupled to the optical transceiver substrate 102. The optical transceiver substrate 102 may include traces 116, where the traces 116 couple the tosa connector pads 214 to the tx connection circuitry 106. The optical transceiver substrate 102 may further include a line 119, wherein the line 119 electrically couples the rosa arrangement 108 to the rx connection 112.

The photonic transmit module arrangement 104 is configured to receive the driving electrical signals TX _ D1 through TX _ D8 and convert the electrical signals into multiplexed optical signals (e.g., signals having channel wavelengths λ 1 through λ 8) via the arrayed waveguide grating 118. The arrayed waveguide grating 118 then outputs the multiplexed optical signal through a transmit fiber 125 having channel wavelengths λ 1 to λ 8. It should be noted that although the example and case (scenario) disclosed herein includes eight channel wavelengths, the present invention is not limited thereto, and modes such as 6, 12, 20 and 24 channels are also within the scope of the present invention.

The photonic transmit module arrangement 104 includes a plurality of laser diode devices 114 and supporting circuitry. Each laser diode device 114 can be electrically coupled to the optical transceiver substrate 102 through the tosa connector pad 214 and used to output a different channel wavelength. The laser diode devices of the light emitting sub-module arrangement 104 may include distributed feedback lasers (DFB), Vertical External-cavity Surface-emitting lasers (VECSEL), or other suitable laser devices.

As further shown in FIG. 1, the multi-channel optical receive sub-module arrangement 108 includes an optical demultiplexer 124, an optical sensor array 126 (e.g., photodiode), a first transimpedance amplifier 128-1 and a second transimpedance amplifier 128-2, wherein the first transimpedance amplifier 128-1 and the second transimpedance amplifier 128-2 are used for amplifying optical signals and converting optical signals into electrical signals. The multi-channel optical receive sub-module arrangement 108 may be disposed on the optical transceiver substrate 102 in an on-board manner such that various components are coupled to and supported by the optical transceiver substrate 102.

The optical demultiplexer 124 in the on-board optical receive sub-module configuration of fig. 1 may then include an arrayed waveguide grating for receiving the optical signal and splitting the optical signal into eight different channel wavelengths. The LRM arrangement 108 may further include a photosensor array 126. As described in detail below, the optical sensor array 126 receives the output of the arrayed waveguide grating 118 by having a plurality of optical sensing devices each mounted to a common submount (common submount) and aligned with a respective output port. Thus, the array of photosensors can comprise a 1 × 8 array, but other configurations having more or less than eight channels are also within the scope of the invention. The photo sensor array 126 may then be electrically coupled to the first transimpedance amplifier 128-1 and the second transimpedance amplifier 128-2, such that electrical signals representing four of the channel wavelengths are provided to the first transimpedance amplifier 128-1 and electrical signals representing the remaining four channel wavelengths are provided to the second transimpedance amplifier 128-2.

In operation, the optical demultiplexer 124 receives optical signals from the receive optical fiber 123 and then provides signals therefrom that are separated according to channel wavelength to the photosensor array 126. The photosensor array 126 then converts the received signals at those channel wavelengths into electrical signals and provides the electrical signals to the first transimpedance amplifier 128-1 and the second transimpedance amplifier 128-2. The first transimpedance amplifier 128-1 and the second transimpedance amplifier 128-2 then amplify the electrical signals RX _ D1 to RX _ D8 and provide the electrical signals RX _ D1 to RX _ D8 to the receive connection circuit 112, wherein the electrical signals RX _ D1 to RX _ D8 correspond to the channel wavelengths of the received signals. The receive connection circuit 112 is electrically connected to the electronic components (e.g., transimpedance amplifier) in the LRU configuration 108. The receiving connection circuit 112 may include a conductive path (conductive path) to provide electrical connection, and the receiving connection circuit 112 may also include additional circuits.

Referring to fig. 2-6, fig. 2-6 show an exemplary optical transceiver module 200. As shown in the figure, the optical transceiver module 200 includes a substrate 202. The substrate 202 includes a first end 203, wherein the first end 203 extends along a longitudinal axis 250 to a second end 204. The substrate 202 further includes at least a first mounting surface 245, and the first mounting surface 245 is opposite to a second mounting surface 246.

As further shown in the drawings and described in detail below, a light-receiving sub-module arrangement 208 disposed on the first mounting surface 245 is adjacent to the first end and includes on-board or integrated configurations. In addition, an optical transmit sub-module arrangement 206 is coupled to the first end of the substrate 202 and includes a plurality of laser elements and optical connectors for outputting signals at a plurality of channel wavelengths. As shown in the figure, the optical transmit sub-module arrangement 206 may be mounted at the edge of the substrate 202. For example, the substrate 202 may include a printed circuit board assembly or other suitable substrate material.

The optical receive sub-module arrangement 208 includes a fiber optic receptacle 210, an intermediate waveguide 211, an input port 225, an optical demultiplexer 224, a photodiode array 226 (shown more clearly in fig. 4 and 6), first and second transimpedance amplifiers 228-1 and 228-2. The various components of the rosa arrangement 208 may be coupled (e.g., directly coupled) to the first mounting surface 245 of the substrate 202. The substrate 202 may thus be stacked under and support each component for mounting. This may advantageously increase the total surface area for dissipating heat during operation of the optical transceiver module 200. Moreover, the relatively small distance between the optical demultiplexer 224, the photodiode array 226, the first transimpedance amplifier 228-1 and the second transimpedance amplifier 228-2 advantageously reduces the number and length of wire bonds compared to other methods, such as using separate and distinct (discrete) optical receive sub-module housings. Therefore, since fewer bonding wires are used for electrical connection during the manufacturing process, the transmission speed of the RF signal can be increased, the power can be increased by up to 2 dB, and the possibility of damaging the device can be reduced.

In one embodiment, the photodiode array 226 may include two 1x4 arrays of photodiodes. In particular, as more clearly shown in FIG. 4, the photodiode array 226 can include a first 1x4 array photodiode and a second 1x4 array photodiode, wherein the first 1x4 array photodiode is mounted to a first photodiode submount 256-1 and the second 1x4 array photodiode is mounted to a second photodiode submount 256-2. It is noted that in one embodiment, a single-piece submount may be used to mount the photodiode array, as further described below with reference to fig. 8A-8C, while providing, for example, a 1x8 array of single-piece structures. The first photodiode submount 256-1 and the second photodiode submount 256-2 may each be mounted to the first mounting surface 245 of the substrate 202. The first photodiode submount 256-1 and the second photodiode submount 256-2 may thus each be in thermal communication with the substrate 202.

The fiber receptacle 210 may be used to receive an optical fiber through a ferrule (not shown). The intermediate waveguide 211, such as an optical fiber, may optically couple the fiber receptacle 210 to the optical demultiplexer 224 through the input port 225. The input port 225 (or input coupling section) may be tilted with respect to the optical demultiplexer 224 by, for example, about 8 degrees, thereby reducing back reflection (back reflection). The optical demultiplexer 224 may comprise an arrayed waveguide grating, for example. Optical demultiplexer 224 is capable of demultiplexing multiple channel wavelengths from an optical signal and includes angled surfaces to direct light along optical path 255 (shown in fig. 5), where optical path 255 extends substantially parallel to long axis 250 toward substrate 202.

As shown more clearly in fig. 5 and 6, the output port 227 of the optical demultiplexer 224 may be optically aligned with the photodiode array 226, so that the separated signals according to the channel wavelengths are transmitted to the photodiode array 226. During fabrication, the optical demultiplexer 224 may be formed, for example, by a semiconductor process, such as a photolithography process that produces a tolerance of + -0.5 microns. Each of the photodiode devices 223 may be coupled to a corresponding plurality of first photodiode submount 256-1 or second photodiode submount 256-2, respectively, such as by die bonding or other suitable means. Next, the first photodiode submount 256-1 and the second photodiode submount 256-2 may be coupled to the substrate 202, for example, by chip bonding with a tolerance of approximately + -10 microns. During installation of the first and second photodiode submounts 256-1 and 256-2, the first and second photodiode submounts 256-1 and 256-2 may be aligned along the X-axis and Y-axis to ensure that the optical output ports 227 are aligned with the photodiode devices 223, respectively.

The photodiode device 223 is, for example, a photodiode and includes a light receiving area or a light sensing area of about 20 microns. The light energy sensed at the region is converted into an electrical current and a signal representative of this current may be output by each photodiode device 223. Light falling outside the light sensing region due to misalignment (misalignment), for example, may cause the signal output from each photodiode device 223 to degrade or be unusable.

Thus, in one embodiment, each photodiode arrangement 223 includes an integrated lens on one side. For example, fig. 7A and 7B present the disassembly and assembly, respectively, of the photodiode submount 702. It is noted that the photodiode pedestal 702 is presented in a monolithic structure. On the other hand, the first and second photodiode submounts 256-1 and 256-2 of the optical transceiver module 200 are presented as two separate and distinct submounts. Configurations of the abutment that can be used such as a multi-piece abutment or a one-piece construction are within the scope of the present invention. The advantage of the multi-piece photodiode submount is that it includes fine-tune alignment adjustments (fine-tune alignment adjustments) individually for a 1x4 array. A multi-piece photodiode submount such as that shown in fig. 7A and 7B can reduce build time (build) since all associated photodiode devices can be calibrated simultaneously along the X-axis and Y-axis. The approaches and examples disclosed herein may be applied to any configuration.

In any case, the photodiode submount 702 in fig. 7A and 7B includes a mounting surface 704. The mounting face includes a plurality of traces disposed thereon for electrically coupling the photodiode device 223 to the photodiode submount 702. The mounting surface further includes a plurality of contacts 708 to securely and electrically couple each of the photodiode devices 223 to each set of contacts 708, wherein the contacts 708 may also be referred to as terminals (terminating). Each set of contacts includes two cathode contacts 712 and an anode contact 714 disposed between the two cathode contacts 712. Other configurations of the contact portion are also within the scope of the present invention. The photodiode base 702 may further include a divider 720. The dividers 720 may have a predetermined width to ensure that each 1x4 array of photodiode devices is separated by a distance such that each 1x4 array is aligned with the output port 227 of the optical demultiplexer 224. The photodiode submount 702 may also include orientation markers 710 for calibration.

Fig. 8A-8C present examples of the photodiode arrangement 223 alone. As shown in fig. 8A, the first side of the photodiode device 223 includes a plurality of cathode contacts 804, an anode contact 806, and a plurality of optical bonding pads (optical bonding pads) 808. A second side of the photodiode arrangement 223 opposite the first side includes an integral lens 802. Thus, the photodiode device 223 may be formed in a monolithic structure with the integrated lens 802 flush or substantially flush with the top surface defining the photodiode device 223. The integrated lens covers at least a portion of the light sensing area of the photodiode arrangement 223 and can increase the tolerance to 50% or more by virtue of the position of the integrated lens itself relative to the associated light sensing area. For example, for a photodiode with a 20 micron light sensing area, the photodiode die bonding can have a tolerance of 10 microns, while a demultiplexer such as an arrayed waveguide grating can have a calibration tolerance of 7 microns. Without the integrated lens according to the present invention, the optical alignment between the demultiplexer and the photodiode may be difficult to achieve with chip bonding. Thus, in the case of a photodiode having a light sensing area of 20 microns, the photodiode provided with an integrated lens increases the alignment tolerance between the demultiplexer and the photodiode, for example, to about ± 20 microns. This advantageously allows the demultiplexer to be used with the optical receive sub-module arrangement disclosed herein even with large differences in the associated tolerances.

The photodiode device 223 can then be coupled to a respective photodiode submount, such as the photodiode submount 702 and the side of the photodiode device 223 facing away from the photodiode submount has an integrated lens 802. Such a configuration of arranging the integrated lens to the photodiode arrangement 223 may be precisely referred to as a back lens (backsidelens).

According to an embodiment of the invention, an optical transceiver module is disclosed. The optical transceiver module includes a substrate and an on-board optical transceiver sub-module arrangement. The substrate has a first end extending to a second end. The substrate is provided with at least one first mounting surface. The on-board optical receive sub-module arrangement includes a photodiode array and an optical demultiplexer. The photodiode array is mounted on the first mounting surface of the substrate. The optical demultiplexer is mounted on the first mounting surface of the substrate. The optical demultiplexer has an optical output port. The optical output port is aligned with and optically coupled to the photodiode array. Each of the plurality of photodiodes in the photodiode array includes an integrated lens to increase an alignment tolerance between the optical demultiplexer and a light sensing area of each of the photodiodes in the photodiode array.

In accordance with another embodiment of the present invention, an optical transceiver is disclosed. The optical transceiver includes a housing, an optical transceiver module, and an optical transmit sub-module arrangement. The shell defines a cavity for accommodating an optical transceiver module. The optical transceiver module is at least partially disposed in the cavity of the housing and includes a substrate and an on-board optical transceiver sub-module arrangement. The substrate has a first end extending to a second end. The substrate is provided with at least one first mounting surface. The on-board light receiving sub-module arrangement includes a photodiode array and an arrayed waveguide grating. The array waveguide grating is mounted on the first mounting surface of the substrate. The arrayed waveguide grating has an optical output port aligned with and optically coupled to the photodiode array. Each of the plurality of photodiodes in the photodiode array includes an integrated lens to increase a calibration tolerance between the arrayed waveguide grating and a light sensing region of each photodiode in the photodiode array. The light emission sub-module is configured to be mounted on a substrate.

In accordance with another embodiment of the present invention, a photodiode device for use in an optical subassembly is disclosed. The photodiode device comprises a base, a plurality of electrical connection parts, a light sensing area and an integrated lens. The base at least has a first side and a second side opposite to each other. The plurality of electrical connection parts are arranged on the first side. The integrated lens is adjacent to the second side and located above the light sensing area, so that a calibration tolerance between an optical demultiplexer and the light sensing area of the light diode device is increased.

While the principles of the invention have been described herein, it will be understood by those skilled in the art that these descriptions are made only by way of example and are not intended to limit the scope of the invention. In addition to the exemplary embodiments described and presented herein, other embodiments are also within the scope of the present invention. Modifications and substitutions will occur to those skilled in the art and are intended to be within the scope of the invention and are limited only by the following claims.