阅读说明：本技术 一种热可调的光开关 (Heat adjustable optical switch ) 是由 吴砺 郑祖赐 刘哲 李阳 于 2021-10-27 设计创作，主要内容包括：本发明公开了一种热可调的光开关,其包括温度控制器和热可调滤波器,所述的热可调滤波器包括光学基体和光学基体上的滤光片膜堆,滤光片膜堆由高折射率膜层和低折射率膜层交替堆叠而成,其高折射率材料为Si:H或SiOxHy。长波通或者短波通滤光膜堆透过率50%处的波长偏移系数大于90 pm/摄氏度,小于300 pm/摄氏度。本发明可以在800-4000 nm波段通过温度调控光开关的带宽和中心波长。(The invention discloses a heat-adjustable optical switch, which comprises a temperature controller and a heat-adjustable filter, wherein the heat-adjustable filter comprises an optical substrate and an optical filter film stack on the optical substrate, the optical filter film stack is formed by alternately stacking high-refractive-index film layers and low-refractive-index film layers, and the high-refractive-index material is Si: H or SiOxHy. The wavelength deviation coefficient at the position of 50% transmittance of the long-wave-pass or short-wave-pass filtering film stack is larger than 90 pm/degree centigrade and smaller than 300 pm/degree centigrade. The invention can adjust and control the bandwidth and the central wavelength of the optical switch through the temperature in the 800-4000nm wave band.)

1. A kind of heat adjustable photoswitch, it includes temperature controller and heat adjustable filter, the said heat adjustable filter includes optical base and optical filter membrane stack on the optical base, the optical filter membrane stack is stacked up by membrane layer of high refractive index and membrane layer of low refractive index alternately; the thermal adjustable optical switch controls the temperature through the temperature controller, so that the thermal adjustable long-wave pass, short-wave pass and band-pass optical filters on the thermal adjustable filter are subjected to spectrum red shift, and the function of the optical switch is realized.

2. A thermally tunable optical switch according to claim 1, wherein: thermal modulation on the optical substrateThe high-refractive index material of the long-wave-pass, short-wave-pass and band-pass filter film stack is Si, H or SiO_xH_yWherein the refractive index of Si: H is more than 3.2 between 1200nm and 1800nm, and the extinction coefficient is less than 5x10^-5。

3. A thermally tunable optical switch according to claim 1, wherein: the low refractive index film layer of the optical filter film stack on the optical substrate is TiO₂、Nb₂O₅、Ta₂O₅、SiO₂One or a mixture of two or more of them.

4. A thermally tunable optical switch according to claim 1, wherein: the optical substrate is made of silicon materials or one or a mixture of more than two of glass, sapphire and toughened glass based on silicon dioxide materials.

5. A thermally tunable optical switch according to claim 1, wherein: the temperature controller consists of a heating element and a radiating element, wherein the heating element is a TEC or resistor heating element, and the radiating element is a radiating fin arranged at the bottom of the heating element.

6. A thermally tunable optical switch according to claim 1, wherein: the optical filter film stack on the optical substrate is composed of any one or more than one of conventional long-wave pass, short-wave pass and band-pass optical filter film stacks and heat-adjustable long-wave pass, short-wave pass and band-pass optical filter film stacks.

7. A thermally tunable optical switch according to claim 1, wherein: the wavelength offset coefficient of 50% of the transmittance of the thermal-adjustable long-wave-pass or short-wave-pass film stack on the optical substrate is greater than 90 pm/DEG C and less than 300 pm/DEG C.

Technical Field

The invention relates to the field of optics and optical communication, in particular to a thermally adjustable optical switch.

Background

The optical switch is one of core devices for realizing an all-optical network, and is mainly used for selection, exchange and modulation of optical signals in optical communication systems, optical fiber sensing systems and other systems. The optical switch mainly adopts MEMS, mechanical, thermo-optical, photoelectric, acousto-optic and bubble technologies. In particular, the MEMS optical switch has the advantages of small volume, high integration level, high response speed and good reliability.

The optical switch based on the traditional optical band-pass filter can select and modulate optical signals by adjusting the incident angle of light rays to realize the function of the optical switch. However, the method depends on mechanization, complex structure, large volume and poor stability on one hand, and on the other hand, the transflective curve of the method changes with the angle and has large loss.

The Chinese invention patent CN112578494 reports a tunable filter based on Si: H, and the filter realizes the tunability of the central wavelength of a transmission band but cannot realize the tunability of the bandwidth of the transmission band by temperature regulation.

Disclosure of Invention

The invention aims to provide an optical switch which is composed of a thermal adjustable long-wave pass, short-wave pass or band-pass filter and is used for adjusting wavelength and bandwidth through temperature.

In order to achieve the purpose, the invention adopts the following technical scheme:

the thermal tunable optical switch comprises a temperature controller and a thermal tunable filter, wherein the thermal tunable filter comprises an optical substrate and an optical filter film stack on the optical substrate, and the optical filter film stack is formed by alternately stacking high-refractive-index film layers and low-refractive-index film layers. The invention controls the temperature through the temperature controller, so that the thermal adjustable long-wave pass, short-wave pass and band-pass filters on the thermal adjustable filter are red-shifted, thereby realizing the function of the optical switch.

Preferably, the high-refractive-index material of the thermally-adjustable long-wave-pass, short-wave-pass and band-pass filter film stack on the optical substrate is Si, H or SiO_xH_yWherein the refractive index of Si: H is more than 3.2 between 1200nm and 1800nm, and the extinction coefficient is less than 5x10^-5。

Preferably, the low refractive index film layer of the filter film stack on the optical substrate is TiO₂、Nb₂O₅、 Ta₂O₅、SiO₂One or a mixture of two or more of them;

preferably, the material of the optical substrate is silicon material or one or a mixture of two or more of glass, sapphire and tempered glass based on silicon dioxide material.

Preferably, the temperature controller is composed of a heating element and a heat dissipation element, wherein the heating element is a TEC or resistor heating element, and the heat dissipation element is a heat dissipation fin arranged at the bottom of the heating element.

Preferably, the optical filter film stack on the optical substrate is composed of a conventional long-wave-pass, short-wave-pass and band-pass optical filter film stack and any one or more than one thermally-adjustable long-wave-pass, short-wave-pass and band-pass optical filter film stack.

Preferably, the wavelength deviation coefficient of 50% of the transmittance of the thermally adjustable long-wave-pass or short-wave-pass film stack on the optical substrate is greater than 90 pm/DEG C and less than 300 pm/DEG C.

The invention can adjust and control the bandwidth and the central wavelength of the optical switch through the temperature in the 800-4000nm wave band.

Drawings

The invention is described in further detail below with reference to the accompanying drawings and the detailed description;

FIG. 1 is a schematic diagram of a thermally tunable optical switch of the present invention;

FIG. 2 is a graph of transmittance versus wavelength for a conventional bandpass filter stack and a thermally tunable long wavelength bandpass filter stack at 25 degrees Celsius for example 1;

FIG. 3 is a graph of wavelength versus temperature for example 1 at 50% transmission in the range of 25 degrees Celsius to 100 degrees Celsius;

FIG. 4 is a graph showing the relationship between transmittance and wavelength at 25 ℃ to 100 ℃ in example 1;

FIG. 5 is a schematic view of an optical switch of example 2 composed of thermally tunable long-pass and short-pass filters;

FIG. 6 is a graph of transmittance versus wavelength for the thermally tunable filter 102-4 long pass filter and the thermally tunable filter 102-5 short pass filter at 25 degrees Celsius for example 2;

fig. 7 is a graph of transmission versus wavelength for example 2 at 25 degrees celsius to 100 degrees celsius for thermally tunable filter 102-4 and 25 degrees celsius for thermally tunable filter 102-5.

FIG. 8 is a graph of transmission versus wavelength for example 2 at 25 degrees Celsius for thermally tunable filter 102-5 to 100 degrees Celsius and for thermally tunable filter 102-4 to 25 degrees Celsius;

FIG. 9 is a graph showing the relationship between the transmission and the wavelength of the tunable filter 102-4 and the long-pass filter 102-5 in example 2 when the temperature of the short-pass film stack is 25 to 100 ℃.

Detailed Description

The invention is further illustrated below with reference to application examples.

As shown in fig. 1, a thermally tunable optical switch has a structure including a temperature controller 101 and a thermally tunable filter 102, and the thermally tunable filter is disposed on the temperature controller 101. The thermally tunable filter 102 includes an optical substrate 102-1 and a filter stack on the optical substrate 102-1, wherein the filter stack is formed by alternately stacking a high refractive index film layer 102-2 and a low refractive index film layer 102-3

The temperature controller 101 is used for controlling the temperature, so that the spectrum of the thermal adjustable long-wave-pass, short-wave-pass and band-pass optical filters on the thermal adjustable filter 102 is red-shifted, and the function of an optical switch is realized.

In a preferred embodiment, the thermally tunable long-pass, short-pass, and band-pass filter stack on the optical substrate is made of Si, H, or SiO with high refractive index_xH_yWherein the refractive index of Si, H is more than 3.2 between 1200nm and 1800nm, and the extinction coefficient is less than 5x10^-5。

The low refractive index film layer of the optical filter film stack on the optical substrate is TiO₂、Nb₂O₅、Ta₂O₅、SiO₂One or a mixture of two or more of them;

the optical substrate is made of silicon materials or one or a mixture of more than two of glass, sapphire and toughened glass based on silicon dioxide materials.

The temperature controller comprises a heating element and a radiating element, wherein the heating element is a resistance heating element, and the radiating element is a radiating fin arranged at the bottom of the heating element.

The optical filter film stack on the optical substrate is composed of any one or more than one of conventional long-wave pass, short-wave pass and band-pass optical filter film stacks and heat-adjustable long-wave pass, short-wave pass and band-pass optical filter film stacks.

The wavelength offset coefficient of 50% of the transmittance of the thermal-adjustable long-wave-pass or short-wave-pass film stack on the optical substrate is greater than 90 pm/DEG C and less than 300 pm/DEG C.

The invention adopts the thermal tunable filter 102 formed by a long-wave pass or short-wave pass filter of a Si-H film process, and the temperature is regulated and controlled by the temperature controller 101 to realize the functions of an optical switch on the bandwidth and the central wavelength of the thermal tunable filter 102.

Example 1

The optical switch of the present embodiment is composed of a thermal tunable short-wave pass filter, and as shown in fig. 1, the optical switch has a structure including a temperature controller 101 and a thermal tunable filter 102, the thermal tunable filter is disposed on the temperature controller 101, and the thermal tunable filter 102 includes an optical substrate, a conventional band-pass filter stack on one side of the optical substrate, and a thermal tunable long-wave pass filter stack on the other side of the optical substrate. The optical base material is WMS-15.

In the embodiment 1, different temperatures are set by the temperature controller 101, so that the spectrum of the corresponding thermally tunable long-wave pass filter on the thermally tunable filter 102 does not undergo red shift at the same temperature due to red shift generated by temperature drift, and the effect of adjusting the center wavelength and bandwidth of the transmission band of the conventional filter stack is achieved.

The black dashed line in FIG. 2 shows the transmittance and wavelength at 25 deg.C of a conventional bandpass filter stack, which is Ta, a high-refractive-index material₂O₅And low refractive index material SiO₂Alternately stacked on a substrate, and having a center wavelength of 1545.25nm and a bandwidth of 24.1nm at a transmittance of 50%.

The order of the alternate stacking of the two refractive index materials and the film system thickness are as follows:

as shown by the black solid line in fig. 2, the relationship between the transmittance and the wavelength of the stack at 25 deg.c is shown, and the high refractive index material is obtainedSi, H and low refractive index material SiO₂Alternately stacked on the substrate, and the wavelength corresponding to a transmittance of 50% is 1532.3 nm.

The order of the alternate stacking of the two refractive index materials and the film system thickness are as follows:

as shown in fig. 3, which is a graph of wavelength versus temperature at 50% transmittance in the range of 25 c to 100 c for a stack of thermally tunable short wavelength pass filter films, the shift coefficient is about 128 pm/c.

Fig. 4 is a graph showing the relationship between transmission and wavelength at 25-100 degrees celsius in this embodiment. The FWHM of this example was 24.1nm at 25 degrees Celsius and the band center wavelength was 1545.25 nm. At 50 degrees Celsius, the FWHM of this example is 21.8nm and the transmission band center wavelength is 1546.4 nm. The FWHM of this example is 15.5nm at 100 degrees Celsius and the band center wavelength is 1549.55 nm.

Example 2

The optical switch comprises two temperature controllers and two thermally tunable filters, wherein the thermally tunable filters are disposed on the temperature controllers.

As shown in fig. 5, in the embodiment 2, different temperature combinations are set by the temperature controllers 101-1 and 101-2, so that the temperature drifts of the corresponding thermally tunable long-wavelength pass spectrum on the thermally tunable filter 102-4 and the corresponding thermally tunable short-wavelength pass spectrum on 102-5 generate red shifts, and the effect of adjusting the center wavelength and the bandwidth of the transmission band is achieved by the red shifts of the different temperature drifts corresponding to different temperatures.

As shown in fig. 5, the two thermally tunable filters 102-4 and 102-5 include an optical substrate, and both sides of the substrate are formed by alternately stacking high refractive index film layers and low refractive index film layers. The optical base material is WMS-15.

As shown by the black dotted line in fig. 6, the transmittance of the short-wavelength pass filter 102-4 at 25 degrees celsius is plotted against the wavelength, and the short-wavelength pass filter is formed by alternately stacking a high refractive index material Si: H and a low refractive index material SiO2 on a substrate, and the wavelength corresponding to the transmittance at 50% is 1570 nm.

The order of the alternate stacking of the two refractive index materials and the film system thickness are as follows:

FIG. 6 is a graph showing the relationship between the transmittance and the wavelength of the long-wave pass filter 102-5 at 25 deg.C, wherein the graph shows the relationship between the high-refractive-index material Si: H and the low-refractive-index material SiO₂Alternately stacked on the substrate, and the wavelength corresponding to 50% transmittance is 1540 nm.

The order of the alternate stacking of the two refractive index materials and the film system thickness are as follows:

example 2 is a transmission band center wavelength and bandwidth variation under three different sets of temperature controls as follows:

when the temperature of the short wave pass film stack of the thermal tunable filter 102-4 is 25 ℃ to 100 ℃ and the temperature of the long wave pass film stack of the thermal tunable filter 102-5 is 25 ℃, the relationship between the transmission and the wavelength of the example 2 is shown in fig. 7. At 25 degrees celsius, the FWHM of this example is 30nm, with a transmission band center wavelength of 1555 nm. At 50 degrees Celsius, the FWHM of this example is 33.2nm and the transmission band center wavelength is 1556.6 nm. The FWHM of this example is 39.6nm at 100 degrees Celsius and the band center wavelength is 1559.8 nm.

When the temperature of the long-wave-pass film stack of the thermal tunable filter 102-5 is 25 to 100 degrees centigrade and the temperature of the short-wave-pass film stack of the thermal tunable filter 102-4 is 25 degrees centigrade, the relation between the transmission and the wavelength of the example 2 is shown in fig. 8. At 25 degrees celsius, the FWHM of this example is 30nm, with a transmission band center wavelength of 1555 nm. At 50 degrees Celsius, the FWHM of this example is 26.8nm and the band center wavelength is 1556.6 nm. The FWHM of this example is 20.4nm at 100 degrees Celsius and the band center wavelength is 1559.8 nm.

When the temperature of the short wave-pass film stack of the thermal tunable filter 102-4 and the temperature of the long wave-pass film stack of the thermal tunable filter 102-5 are the same and are 25 degrees celsius to 100 degrees celsius in example 2, the relationship between the transmission and the wavelength is as shown in fig. 9. At 25 degrees celsius, the FWHM of this example is 30nm, with a transmission band center wavelength of 1555 nm. At 50 degrees Celsius, the FWHM of this example is 30nm and the band center wavelength is 1558.2 nm. The FWHM of this example is 30nm at 100 degrees Celsius and the band center wavelength is 1564.6 nm.

While the invention has been described in connection with the embodiments illustrated in the drawings, it is to be understood that the invention is not limited to the disclosed embodiments, which are intended as illustrative rather than restrictive, and that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; the modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present invention, and the technical solutions are all covered by the claims and the specification of the present invention.