High-resolution photonic thermometer article

Patent metadata

Field	Value
Publication number	US-2020103594-A1
Application number	US-201916589793-A
Country	US
Kind code	A1
Filing date	Oct 1, 2019
Priority date	Oct 1, 2018
Publication date	Apr 2, 2020
Grant date	—

Abstract

A high-resolution photonic thermometer article performs high-resolution thermometry and includes: a light source; a photonic thermometer with a waveguide and a photonic crystal cavity that stores light; a photodetector in communication with the photonic thermometer; a phase sensitive detector in communication with the photodetector and that: receives the photodetector signal from the photodetector; receives a reference frequency signal; and produces a lock signal from the photodetector signal, based on the reference frequency signal; a local oscillator in communication with the phase sensitive detector and that produces the reference frequency signal; and a servo controller in communication with the phase sensitive detector and local oscillator and that: receives the lock signal from the phase sensitive detector; receives the reference frequency signal from the local oscillator; and produces the control signal such that absorption power of the photonic crystal is maximized through wavelength control of the light source by the control signal.

First claim

What is claimed is:

1 . A high-resolution photonic thermometer article for performing high-resolution thermometry, the high-resolution photonic thermometer article comprising:
a light source that:
receives a control signal; and
produces, based on the control signal, a primary light that comprises a primary wavelength and a primary power;
a photonic thermometer in communication with the light source and comprising:
a waveguide in communication with a photonic crystal cavity and comprising:
an input light coupler that receives the primary light;
a photonic crystal cavity in communication with the input light coupler and that:
interacts with the primary light from the input light coupler; and
stores the primary light when the primary wavelength matches a resonance frequency of the photonic crystal cavity, such that an amount of primary light stored in the photonic crystal cavity comprises an absorption power; and

the waveguide further comprising an output light coupler in communication with the photonic crystal cavity and that:
receives the primary light as thermometer light after the primary light has interacted with the photonic crystal cavity, the thermometer light comprising a transmission power that is indirectly proportional to the absorption power of the primary light stored in the photonic crystal cavity;

a photodetector in communication with the photonic thermometer and that:
receives the thermometer light from the photonic thermometer; and
produces a photodetector signal from the thermometer light;
a phase sensitive detector in communication with the photodetector and that:
receives the photodetector signal from the photodetector;
receives a reference frequency signal; and
produces a lock signal from the photodetector signal, based on the reference frequency signal;
a local oscillator in communication with the phase sensitive detector and that produces the reference frequency signal; and
a servo controller in communication with the phase sensitive detector and the local oscillator and that:
receives the lock signal from the phase sensitive detector;
receives the reference frequency signal from the local oscillator; and
produces the control signal from the lock signal and the reference frequency signal such that the absorption power is maximized through wavelength control of the light source by the control signal.

2 . The high-resolution photonic thermometer article of claim 1 , wherein the photonic thermometer further comprises a substrate on which the input light coupler and photonic crystal cavity are disposed.

3 . The high-resolution photonic thermometer article of claim 2 , further comprising a V-groove fiber array disposed on the substrate and comprising a first optical fiber in communication with the input light coupler and that provides the primary light to the input light coupler; and
a second optical fiber in communication with the output light coupler and that receives the thermometer light from the output light coupler.

4 . The high-resolution photonic thermometer article of claim 1 , further comprising a transducer electrically interposed between and in communication with the light source and the servo controller and that:
receives the control signal from the servo controller; produces a transduction control signal based on the control signal; and communicates the transduction control signal to the light source to control production of the primary wavelength by the light source.

5 . The high-resolution photonic thermometer article of claim 1 , further comprising a wavelength meter in communication with the light source and that receives the primary light from the light source and determines a wavelength of the primary wavelength.

6 . The high-resolution photonic thermometer article of claim 1 , further comprising an isolator, an optical attenuator, a polarization controller, or a combination of at least one of the foregoing optical elements in communication with the light source and that receives the primary light and varies a property of the primary light.

7 . The high-resolution photonic thermometer article of claim 1 , further comprising an optical power meter in communication with the photonic thermometer and that receives the thermometer light from the photonic thermometer and determines the transmission power.

8 . The high-resolution photonic thermometer article of claim 1 , wherein the waveguide comprises a bus waveguide separated from the photonic crystal cavity by a distance that provides for evanescent coupling between the bus waveguide and the photonic crystal cavity.

9 . The high-resolution photonic thermometer article of claim 1 , wherein the waveguide comprises a direct-couple waveguide in which the photonic crystal cavity is interposed between the input light coupler and the output light coupler.

10 . The high-resolution photonic thermometer article of claim 1 , wherein the waveguide comprises a reflection photonic crystal.

11 . The high-resolution photonic thermometer article of claim 1 , further comprising a heat exchanger in thermal communication with the photonic thermometer.

12 . The high-resolution photonic thermometer article of claim 11 , further comprising a tube in which the photonic thermometer and heat exchanger are disposed.

13 . The high-resolution photonic thermometer article of claim 12 , further comprising an inert gas disposed in the tube, wherein the inert gas, the photonic thermometer, and the heat exchanger are hermetically sealed in the tube.

14 . The high-resolution photonic thermometer article of claim 1 , wherein the photonic crystal cavity comprises:
a first modulated Bragg mirror comprising a first set of a plurality of photonic apertures; and a second modulated Bragg mirror in communication with the first modulated Bragg mirror and comprising a second set of a plurality of photonic apertures, wherein the photonic apertures in the first set:
independently comprise a radius; and
are arranged sequentially by a size of the radius of each photonic aperture such that a radial size of sequential photonic apertures decreases along a first taper direction that is directed away from the second . 2 ;
the photonic apertures in the second set:
independently comprise a radius; and
are arranged sequentially in a row by a size of the radius of each photonic aperture such that a radial size of sequential photonic apertures decreases along a second taper direction that is directed away from the first set; and
the first set and the second set are adjacently disposed at a zero-length cavity that is an origin of the first taper direction and the second taper direction.

15 . A process for making the high-resolution photonic thermometer article of claim 14 , the process comprising:
forming the waveguide on the substrate; determining a photonic band gap between a dielectric band edge function f1 and an air band edge function f2 for the photonic crystal cavity as a function of the size of the radius of the photonic apertures; selecting a resonance frequency f res determining a maximum aperture radius R max such that f1(R max )=F res selecting a minimum aperture radius R min ; selecting a number N of pairs of photonic apertures; determining a photonic mirror strength G as a function of radius r i of photonic apertures for selected resonance frequency f res so that G i ={G(r i ), i=1, 2, . . . , N}; forming the photonic crystal cavity on the substrate; and tapering the radii of the photonic apertures in the photonic crystal cavity from the maximum aperture radius R max to

Assignees

• Government Of The Us Secretary Of Commerce

Inventors

• Klimov Nikolai Nikolaevich
• Douglass Kevin O'Connell
• Ahmed Zeeshan

Classifications

• G02B6/30 Primary

  for use between fibre and thin-film device · CPC title

• G02B6/1225

  comprising photonic band-gap structures or photonic lattices · CPC title

• G02B2006/12142

  Modulator · CPC title

• G02B1/005

  made of photonic crystals or photonic band gap materials (photonic band-gap structures or photonic lattices in integrated optics G02B6/1225; photonic band-gap structures or photonic lattices in optical fibres G02B6/02295) · CPC title

• G02B2006/12135

  Temperature control · CPC title