Thermally Tunable Optical Filter with Single Crystalline Spacer Fabricated by Fusion Bonding
A thermally tunable Fabry-Perot optical filter includes a single crystalline sheet resistance heater layer. A single crystalline semiconductor spacer layer is positioned proximate to and in thermal communication with the single crystalline sheet resistance heater layer. A first distributed Bragg reflector is positioned proximate to a first surface of the single crystalline semiconductor spacer layer. A second distributed Bragg reflector is positioned proximate to a second surface of the single crystalline semiconductor spacer layer.
1 . A thermally tunable Fabry-Perot optical filter comprising:
a. a single crystalline sheet resistance heater layer;
b. a single crystalline semiconductor spacer layer positioned proximate to and in thermal communication with the single crystalline sheet resistance heater layer;
c. a first distributed Bragg reflector positioned proximate to a first surface of the single crystalline semiconductor spacer layer; and
d. a second distributed Bragg reflector positioned proximate to a second surface of the single crystalline semiconductor spacer layer.
2 . The optical filter of claim 1 wherein the single crystalline semiconductor spacer layer comprises single crystalline (c-Si) silicon.
3 . The optical filter of claim 1 wherein the single crystalline semiconductor spacer layer comprises single crystalline germanium.
4 . The optical filter of claim 1 wherein the single crystalline semiconductor spacer layer comprises a III-V semiconductor.
5 . The optical filter of claim 1 wherein the single crystalline semiconductor spacer layer comprises a II-VI semiconductor.
6 . The optical filter of claim 1 wherein the first and second distributed Bragg reflector comprise alternating layers of at least two of silicon oxide, silicon nitride, and silicon oxynitride.
7 . The optical filter of claim 1 wherein the single crystalline sheet resistance heater layer is positioned adjacent to the single crystalline semiconductor spacer layer in a vertical direction.
8 . The optical filter of claim 1 wherein the single crystalline sheet resistance heater layer is positioned co-planar with the single crystalline semiconductor spacer layer.
9 . The optical filter of claim 8 wherein the single crystalline sheet resistance heater layer is a doped region of the single crystalline semiconductor spacer layer.
10 . The optical filter of claim 8 wherein the single crystalline sheet resistance heater layer is integrated into the single crystalline semiconductor spacer layer.
11 . The optical filter of claim 1 wherein the thermally tunable Fabry-Perot optical filter is formed on a glass substrate.
12 . The optical filter of claim 1 wherein a first and second portion of the thermally tunable Fabry-Perot optical filter are fusion bonded.
13 . A thermally tunable Fabry-Perot optical filter comprising:
a. a single crystalline sheet resistance heater layer;
b. a spacer layer positioned proximate to and in thermal communication with the single crystalline sheet resistance heater layer, wherein the spacer layer has a thermo-optic coefficient greater than 10 −4 , is substantially optical transparent to optical signals being filtered, and is thermally stable during fabrication;
c. a first distributed Bragg reflector positioned proximate to a first surface of the spacer layer; and
d. a second distributed Bragg reflector positioned proximate to a second surface of the spacer layer.
14 . The optical filter of claim 13 wherein the spacer layer comprises a polymer.
15 . The optical filter of claim 13 wherein the spacer layer comprises a single crystal material.
16 . The optical filter of claim 13 wherein the first and second distributed Bragg reflectors comprise alternating layers of at least two of silicon oxide, silicon nitride, and silicon oxynitride.
17 . The optical filter of claim 13 wherein the single crystalline sheet resistance heater layer is positioned adjacent to the spacer layer in a vertical direction.
18 . The optical filter of claim 13 wherein the single crystalline sheet resistance heater layer is positioned co-planar with the spacer layer.
19 . The optical filter of claim 13 wherein the single crystalline sheet resistance heater layer is integrated into the spacer layer.
20 . The optical filter of claim 13 wherein the thermally tunable Fabry-Perot optical filter is formed on a glass substrate.
21 . The optical filter of claim 13 wherein a first and second portion of the thermally tunable Fabry-Perot optical filter are fusion bonded.
22 . A method of fabricating a thermally tunable Fabry-Perot optical filter, the method comprising:
a. forming a single-crystalline semiconductor cavity on a first half section of the Fabry-Perot optical filter;
b. depositing a first distributed Bragg reflector on the first half section of the tunable optical filter;
c. forming a single crystalline heater on a second half section of the tunable optical filter;
d. depositing a second distributed Bragg reflector on the second half section of the tunable optical filter; and
e. fusion bonding the first and second half sections of the thermally tunable Fabry-Perot optical filter together, thereby forming the Fabry-Perot optical filter.
23 . The method of claim 22 further comprising forming one half of a quarter wavelength of dielectric material on each of the first and second half sections of the thermally tunable Fabry-Perot optical filter prior to fusion bonding.
24 . The method of claim 22 further comprising forming a quarter wavelength of dielectric material on the second half section of the thermally tunable Fabry-Perot optical filter cavity prior to fusion bonding.
25 . The method of claim 22 wherein the semiconductor comprises single crystalline (c-Si) silicon.
26 . A method of fabricating a thermally tunable Fabry-Perot optical filter, the method comprising:
a. forming a single-crystalline semiconductor cavity on a first half section of the Fabry-Perot optical filter;
b. forming a single crystalline heater on a second half section of the tunable optical filter;
c. depositing a second distributed Bragg reflector on the second half section of the tunable optical filter;
d. fusion bonding the first and second half sections of the thermally tunable Fabry-Perot optical filter together; and
e. depositing a first Bragg reflector on the single-crystalline semiconductor cavity, thereby forming the Fabry-Perot optical filter.
27 . The method of claim 26 further comprising forming one half of a quarter wavelength of dielectric material on each of the first and second half sections of the thermally tunable Fabry-Perot optical filter prior to fusion bonding.
28 . The method of claim 26 wherein the semiconductor comprises single crystalline (c-Si) silicon.
29 . A method of fabricating a thermally tunable Fabry-Perot optical filter, the method comprising:
a. forming a single-crystalline semiconductor cavity on a first half section of the Fabry-Perot optical filter;
b. depositing a first distributed Bragg reflector on a first surface of the single-crystalline semiconductor cavity;
c. depositing a second distributed Bragg reflector on a second surface of the single-crystalline semiconductor cavity;
d. forming a single crystalline heater on a second half section of the tunable optical filter; and
e. fusion bonding the first and second half sections of the thermally tunable Fabry-Perot optical filter together.
30 . The method of claim 29 further comprising forming one half of a quarter wavelength of dielectric material on each of the first and second half sections of the Fabry-Perot optical filter prior to fusion bonding.
31 . The method of claim 29 further comprising forming a quarter wavelength of dielectric material on the first half of the Fabry-Perot optical filter cavity prior to fusion bonding.
32 . The method of claim 29 wherein the semiconductor comprises single crystalline (c-Si) silicon.
33 . A method of fabricating a thermally tunable Fabry-Perot optical filter, the method comprising:
a. forming a single-crystalline semiconductor cavity;
b. forming at least one single crystalline heater adjacent to the single-crystalline semiconductor cavity in a co-planar direction;
c. depositing a first distributed Bragg reflector on a first surface of the co-planar single-crystalline semiconductor cavity and the at least one single crystalline heater;
d. depositing a quarter wavelength of dielectric material on the co-planar single-crystalline semiconductor cavity and the at least one single crystalline heater; and
e. depositing a second distributed Bragg reflector on the quarter wavelength of dielectric material.
34 . The optical filter of claim 33 wherein the semiconductor comprises single crystalline (c-Si) silicon.