# US 11,442,148 B2 · High temperature and high dynamic bandwidth photonic sensor for gas flow rate, temperature, and pressure measurement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,148 B2 - Document ID: US11442148B2 - Status: Granted - Kind: B2 - Application number: 16/569,581 - Filed: 2019-09-12 - Published: 2021-03-18 - Granted: 2022-09-13 - Earliest claimed: 2019-09-12 - Assignees: Honeywell International Inc. - Applicants: Honeywell International Inc. - Inventors: Steven Tin; Chad Fertig; Matthew Wade Puckett; Neil A. Krueger; Jianfeng Wu - Web page: https://patentgrep.com/patent/US11442148B2 ## CPC - G01S 7/4816: {of receivers alone} - G01S 7/4811: {common to transmitter and receiver} - G01S 7/4818: {using optical fibres} - G01S 17/10: using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) - G02B 6/29325: {of the slab or planar or plate like form, i.e. confinement in a single transverse dimension only (integrated circuit planar waveguide arrangements G02B6/12007; specially adapted for lighting G02B6/0011)} - G02B 6/29389: {Bandpass filtering, e.g. 1x1 device rejecting or passing certain wavelengths (G02B6/2938 takes precedence)} - G02B 6/4215: {the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers (G02B6/4246 takes precedence)} - G01D 3/0365: {the undesired influence being measured using a separate sensor, which produces an influence related signal} - G01K 11/3206: at discrete locations in the fibre, e.g. using Bragg scattering - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) ## Abstract A sensor system comprises a pulsed light source, and a passive sensor head chip in communication with the light source. The sensor head chip includes a first photonics substrate, a transmitting optical component on the first photonics substrate and configured to couple a pulse, transmitted through a first optical fiber from the light source, into a region of interest; and a receiving optical component on the first photonics substrate and configured to couple backscattered light, received from the region of interest, into a second optical fiber. A signal processing chip communicates with the sensor head chip and light source. The signal processing chip includes a second photonics substrate and comprises a passive optical filter array that receives the backscattered light from the second optical fiber. The filter array includes notch filters in communication with each other and operative for frequency selection; and optical detectors respectively coupled to the notch filters. ## Claims ### Claim 1 A sensor system, comprising: a pulsed light source operative to emit light pulses at a selected wavelength; a passive sensor head chip in optical communication with the pulsed light source, the passive sensor head chip including a first photonics substrate and comprising: a transmitting optical component on the first photonics substrate and optically coupled to a first optical fiber, the transmitting optical component configured to couple a light pulse, transmitted through the first optical fiber from the pulsed light source, into a region of interest; and a receiving optical component on the first photonics substrate and optically coupled to a second optical fiber, the receiving optical component configured to couple backscattered light, received from the region of interest, into the second optical fiber; and a signal processing chip in optical communication with the passive sensor head chip and the pulsed light source, the signal processing chip including a second photonics substrate and comprising: a passive optical filter array on the second photonics substrate, the passive optical filter array configured to receive the backscattered light from the second optical fiber and a reference pulse from the pulsed light source, wherein the passive optical filter array includes: a plurality of optical notch filters in optical communication with each other, the optical notch filters operative for frequency selection; and a plurality of optical detectors each respectively coupled to an output of one of the optical notch filters; wherein the passive optical filter array is operative to perform frequency spectrum decomposition of the received backscattered light into a plurality of signals used for data extraction and processing to determine one or more parameters of a gas in the region of interest. ### Claim 2 (depends on 1) The sensor system of claim 1, wherein: the pulsed light source comprises a pulsed laser; the transmitting optical component comprises a first grating coupler; and the receiving optical component comprises a second grating coupler. ### Claim 3 (depends on 1) The sensor system of claim 1, wherein the first and second photonics substrates comprise silicon photonics substrates. ### Claim 4 (depends on 2) The sensor system of claim 2, wherein the first and second grating couplers comprise silicon photonics grating couplers. ### Claim 5 (depends on 1) The sensor system of claim 1, wherein: the passive sensor head chip is configured to be located in a first higher temperature zone associated with the region of interest; and the signal processing chip is configured to be located in a second lower temperature zone away from the region of interest. ### Claim 6 (depends on 1) The sensor system of claim 1, wherein the passive optical filter array is configured to receive the reference pulse from a third optical fiber coupled between the first optical fiber and the second optical fiber, wherein the reference pulse provides a reference for Doppler shift. ### Claim 7 (depends on 1) The sensor system of claim 1, wherein each of the optical notch filters is operative to pass a selected frequency from a frequency spectrum to a respective one of the optical detectors. ### Claim 8 (depends on 1) The sensor system of claim 1, wherein the optical notch filters each comprise: a waveguide structure including a first waveguide and a second waveguide, the waveguide structure comprising: an input port located at a first end of the first waveguide; a reflection port located at a first end of the second waveguide and adjacent to the input port; a drop port located at an opposite second end of the first waveguide; and a grating-assisted directional coupler located in a central portion of the waveguide structure between the input port and the drop port, the grating-assisted directional coupler including a periodic grating structure on each of the first and second waveguides. ### Claim 9 (depends on 8) The sensor system of claim 8, wherein: the first waveguide is configured to receive light injected into the input port and direct the light to the grating-assisted directional coupler; and the periodic grating structure of the grating-assisted directional coupler is configured to produce a pi phase shift, which is an abrupt change in a spatial pattern of waveguide modulation, such that a periodic structure of the waveguide modulation is shifted in spatial phase by pi radians on either side of an interface, that generates a confined field of the light at a resonance wavelength, with the light circulating around the pi phase shift; wherein a selected wavelength of the light is transmitted to the drop port, and all other wavelengths of the light exit through the reflection port. ### Claim 10 (depends on 1) The sensor system of claim 1, further comprising a data processing unit coupled to an output of the signal processing chip, the data processing unit operative to determine the one or more parameters of the gas in the region of interest. ### Claim 11 (depends on 1) The sensor system of claim 1, wherein the one or more parameters of the gas in the region of interest include gas temperature, gas pressure, or gas flow rate. ### Claim 12 (depends on 1) The sensor system of claim 1, wherein the sensor system is implemented in a light detection and ranging (LiDAR) sensor system. ### Claim 13 A sensor system, comprising: a sensor chip comprising a photonics substrate; a pulsed light source on the photonics substrate, the pulsed light source operative to emit light pulses at a selected wavelength; a first grating coupler on the photonics substrate and in optical communication with the pulsed light source, the first grating coupler configured to couple a light pulse, transmitted from the pulsed light source, into a region of interest; a second grating coupler on the photonics substrate, the second grating coupler configured to receive backscattered light from the region of interest; and a passive optical filter array on the photonics substrate and in optical communication with the second grating coupler, the passive optical filter array configured to receive the backscattered light from the second grating coupler, and a reference pulse from the pulsed light source, wherein the passive optical filter array comprises: a plurality of optical notch filters in optical communication with each other, the optical notch filters operative for frequency selection; and a plurality of optical detectors each respectively coupled to an output of one of the optical notch filters; wherein the passive optical filter array is operative to perform frequency spectrum decomposition of the received backscattered light into a plurality of signals used for data extraction and processing to determine one or more parameters of a gas in the region of interest. ### Claim 14 (depends on 13) The sensor system of claim 13, wherein: the pulsed light source comprises a pulsed laser; and the photonics substrate comprises a silicon photonics substrate. ### Claim 15 (depends on 13) The sensor system of claim 13, wherein each of the optical notch filters is operative to pass a selected frequency from a frequency spectrum to a respective one of the optical detectors. ### Claim 16 (depends on 13) The sensor system of claim 13, wherein the optical notch filters each comprise: a waveguide structure including a first waveguide and a second waveguide, the waveguide structure comprising: an input port located at a first end of the first waveguide; a reflection port located at a first end of the second waveguide and adjacent to the input port; a drop port located at an opposite second end of the first waveguide; and a grating-assisted directional coupler located in a central portion of the waveguide structure between the input port and the drop port, the grating-assisted directional coupler including a periodic grating structure on each of the first and second waveguides. ### Claim 17 (depends on 16) The sensor system of claim 16, wherein: the first waveguide is configured to receive light injected into the input port and direct the light to the grating-assisted directional coupler; and the periodic grating structure of the grating-assisted directional coupler is configured to produce a pi phase shift, which is an abrupt change in a spatial pattern of waveguide modulation, such that a periodic structure of the waveguide modulation is shifted in spatial phase by pi radians on either side of an interface, that generates a confined field of the light at a resonance wavelength, with the light circulating around the pi phase shift; wherein a selected wavelength of the light is transmitted to the drop port, and all other wavelengths of the light exit through the reflection port. ### Claim 18 (depends on 13) The sensor system of claim 13, further comprising a data processing unit coupled to an output of the sensor chip, the data processing unit operative to determine the one or more parameters of the gas in the region of interest. ### Claim 19 (depends on 13) The sensor system of claim 13 wherein the one or more parameters of the gas that are determined for the region of interest include gas temperature, gas pressure, or gas flow rate. ### Claim 20 (depends on 13) The sensor system of claim 13, wherein the sensor system is implemented in a light detection and ranging (LiDAR) sensor system.