Liquid sensing systems and methods using a ring resonator sensor
A sensor system having a multi-pass interaction region is disclosed. The system includes an input region, a multi-pass region, and an output region. The input region is configured to receive emitted light. The multi-pass region is coupled to the input region and is configured to absorb portions of the emitted light according to a specimen proximate the multi-pass region. The output region is coupled to the multi-pass region and is configured to provide interacted light from the multi-pass region.
1. A sensor system having a multi-pass interaction region, the system comprising:
an input region configured to receive emitted light;
a multi-pass region coupled to the input region, wherein the multi-pass region is configured to cause the emitted light to pass through the multi-pass region multiple times and to absorb portions of the emitted light according to a specimen proximate the multi-pass region, and wherein the multi-pass region is comprised of a periodic structure of two types and has an absorption rate based on specimen characteristics and the periodic structure;
an output region coupled to the multi-pass region, the output region configured to provide interacted light from the multi-pass region; and
a flexible membrane configured to support the input region, the multi-pass region and the output region, wherein the flexible membrane includes a honeycomb structure on its back side with respect to the input region, the multi-pass region and the output region.
2. The system of claim 1 , wherein the input region has a tapered shape.
3. The system of claim 1 , wherein the input region has a linear shape.
4. The system of claim 1 , wherein the input region has grating configured to receive the emitted light off plane.
5. The system of claim 1 , further comprising a light source configured to provide the emitted light at selected wavelengths.
6. The system of claim 1 , wherein the emitted light has an infra-red wavelength.
7. The system of claim 1 , wherein the multi-pass region has a bend configured to permit multiple passes of at least a portion of the emitted light.
8. The system of claim 1 , wherein the multi-pass region is circular and has a radius according to a selected wavelength of the emitted light.
9. The system of claim 1 , further comprising a throughput port coupled to the multi-pass region.
10. The system of claim 1 , wherein the output region is in-line with the input region.
11. The system of claim 1 , further comprising a detector configured to measure the interacted light from the output region.
12. The system of claim 11 , further comprising a control unit configured to obtain a measurement of the interacted light from the detector and to determine chemical properties of a specimen proximate the multi-pass region.
13. The system of claim 1 , wherein the multi-pass region is comprised of polymethacrylmethylimide (PMMI) and is amorphous and has a transmittance of about 90% at a thickness of 3 mili-meters.
14. The system of claim 1 , wherein the absorption rate is further based on temperature and age of the specimen.
15. The system of claim 1 , wherein the flexible membrane is comprised of silicon nitride.
16. A sensor system having a multi-pass interaction region, the system comprising:
a sensor having:
a light source configured to emit light at a selected wavelength;
a waveguide formed of photonic crystal and supported by a flexible membrane and configured to receive the emitted light and absorb a portion of the light according to a specimen, and to provide interacted light, wherein the flexible membrane includes a honeycomb structure on its back side with respect to the waveguide, wherein the photonic crystal is a periodic structure of two types of materials arranged in a periodic lattice and has an absorption rate based on specimen characteristics and the periodic structure; and
a detector configured to measure the interacted light from the waveguide; and
a control unit coupled to the sensor and configured to determine properties of the specimen according to the measured light and the emitted light.
17. The system of claim 16 , wherein the waveguide has a bended portion configured to cause at least a portion of the emitted light to travel through in multiple passes.
18. The system of claim 16 , wherein the waveguide includes a multi-pass interaction region having a circular shape, wherein the circular shape is configured for the selected wavelength.
19. The system of claim 16 , further comprising an interface coupled to the sensor and the control unit.
20. A method of operating a sensor having a multi-pass interaction region, the method comprising:
selecting a wavelength for detection;
configuring a waveguide with a multi-pass interaction region according to the selected wavelength, wherein the multi-pass interaction region is a periodic structure of two types of materials arranged in a periodic lattice and has an absorption rate based on specimen characteristics and the periodic structure;
supporting the waveguide with a flexible membrane, wherein the flexible membrane includes a honeycomb structure on its back side with respect to the waveguide;
receiving light having the selected wavelength at the waveguide;
interacting the received light within the multi-pass interaction region; and
measuring the interacted light from the waveguide.
21. The method of claim 20 , wherein selecting the wavelength includes selecting the wavelength to detect chemical and environmental properties.
22. The method of claim 20 , wherein interacting the received light includes interacting the received light with a specimen proximate to the multi-pass interaction region, wherein the specimen is a liquid.
23. The method of claim 20 , further comprising comparing the measured light with the received light to detect a specimen.