Spectrometer including tunable on-chip laser and spectrum measurement method

Patent metadata

Field	Value
Publication number	US-2021121068-A1
Application number	US-202017021157-A
Country	US
Kind code	A1
Filing date	Sep 15, 2020
Priority date	Oct 25, 2019
Publication date	Apr 29, 2021
Grant date	—

Abstract

A spectrometer may include: a tunable on-chip laser source configured to irradiate a biological tissue with laser radiation; a photodetector configured to receive the laser radiation reflected from the biological tissue; and at least one processor. The tunable on-chip laser source may include: a semiconductor gain chip having a gain bandwidth for operating the tunable on-chip laser source in a predetermined wavelength range; and a plurality of resonator cavities connected between the semiconductor gain chip and the at least one processor, and configured to perform a coarse high-speed measurement and a fine measurement to measure a spectrum of the laser radiation reflected from the biological tissue.

First claim

What is claimed is:

1 . A spectrometer comprising:
a tunable on-chip laser source configured to irradiate a biological tissue with laser radiation; a photodetector configured to receive the laser radiation reflected from the biological tissue; and at least one processor; wherein the tunable on-chip laser source comprises:
a semiconductor gain chip having a gain bandwidth for operating the tunable on-chip laser source in a predetermined wavelength range;
a plurality of resonator cavities connected between the semiconductor gain chip and the at least one processor, and comprising a first resonator cavity and a second resonator cavity;
wherein each of the plurality of resonator cavities comprises a waveguide and a plurality of tunable filters to generate lights having different wavelengths in accordance with parameters of the plurality of tunable filters of each of the plurality of resonator cavities, as the laser radiation to be emitted to the biological tissue, wherein the first resonator cavity comprises a first tunable filter among the plurality of tunable filters, and is configured to perform a coarse high-speed measurement to measure a spectrum of the laser radiation reflected from the biological tissue while the biological tissue is irradiated by the laser radiation generated by the first tunable filter of the first resonator cavity, and wherein the second resonator cavity comprises a second tunable filter among the plurality of tunable filters, and is configured to perform a fine measurement to measure the spectrum of the laser radiation reflected from the biological tissue while the biological tissue is irradiated by the laser radiation generated by the second tunable filter.

2 . The spectrometer according to claim 1 , wherein the waveguide of each of the plurality of resonator cavities is ended with a Sagnac mirror providing a feedback loop between each of the plurality of resonator cavities and the semiconductor gain chip.

3 . The spectrometer according to claim 1 , comprising
metal heating elements located in the plurality of resonator cavities and configured to receive voltage from an external source, and a thermo-optic control circuit configured to tune a wavelength of the plurality of resonator cavities by applying the voltage to the metal heating elements.

4 . The spectrometer according to claim 1 , further comprising
a plurality of electro-optic control circuits configured to tune a wavelength of the plurality of resonator cavities by applying an electric field to the plurality of resonator cavities to change an effective refractive index of the plurality of resonator cavities and a transmission spectrum of the laser radiation emitted from the spectrometer.

5 . The spectrometer according to claim 1 , further comprising
a plurality of acousto-optic control circuits, configured to tune a wavelength of the plurality of resonator cavities, by exposing the plurality of resonator cavities to ultrasonic vibrations from an external source.

6 . The spectrometer according to claim 1 , wherein the semiconductor gain chip having the gain bandwidth for operating the tunable on-chip laser source in the predetermined wavelength range is a first semiconductor gain chip having a first gain bandwidth for operating the tunable on-chip laser source in the predetermined wavelength range,
wherein the spectrometer comprises an array of semiconductor gain chips having different gain bandwidths to provide sweeping along a wavelength in an extended wavelength range that is wider than the predetermined wavelength range, and wherein the array of semiconductor gain chips having the different gain bandwidths comprises the first semiconductor gain chip having the first gain bandwidth.

7 . The spectrometer according to claim 1 , further comprising a modulator configured to control the gain bandwidth of the semiconductor gain chip.

8 . The spectrometer according to claim 1 , further comprising a feedback control circuit and wavelength calibration circuits to calibrate a wavelength of the spectrometer in real time.

9 . The spectrometer according to claim 1 , further comprising a splitter configured to connect the semiconductor gain chip to the plurality of resonator cavities.

10 . The spectrometer according to claim 1 , wherein the first resonator cavity comprises a first mirror that is paired with the first tunable filter, and the second resonator cavity comprises a second mirror that is paired with the second tunable filter.

11 . A method of obtaining bio information by using a spectrometer comprising a plurality of resonator cavities, the plurality of resonator cavities comprising a first resonator cavity and a second resonator cavity, the method comprising:
irradiating a biological tissue with a first laser radiation generated by a first tunable filter of the first resonator cavity, while the first resonator cavity performs a coarse high-speed measurement to measure a spectrum of the first laser radiation reflected from the biological tissue; irradiating the biological tissue with a second laser radiation generated by a second tunable filter of the second resonator cavity while the second resonator cavity performs a fine low-speed measurement to measure a spectrum of the second laser radiation reflected from the biological tissue; and obtain the bio information based on the coarse high-speed measurement and the fine low-speed measurement.

12 . The method according to claim 11 , further comprising
tuning an irradiation wavelength in a waveguide of the first resonator cavity by thermo-optical tuning a wavelength of the first and the second tunable filters by heating the waveguide in the first resonator cavity.

13 . The method according to claim 11 , further comprising
electro-optical tuning a wavelength of the first and the second tunable filters by changing a refractive index of a waveguide of the first resonator cavity by applying an external electric field to the waveguide.

14 . The method according to claim 11 , further comprising
acousto-optic tuning a wavelength of the first and the second tunable optical filters by applying ultrasonic vibrations to a waveguide of the first resonator cavity to change an effective transmission spectrum of the waveguide of the first resonator cavity.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lantsov Alexey Dmitrievich
• SHCHEKIN Alexey Andreevich
• Koptyaev Sergey Nikolaevich
• ANIKANOV Alexey Grigorievich
• RYABKO Maksim Vladimirovich
• IVSHIN Pavel Alexandrovich
• GRIGORIEV Vasiliy Viktorovich
• KOPYSOVA Tatyana Igorevna

Classifications

• G01J2003/106

  the two sources being alternating or selectable, e.g. in two ranges or line:continuum · CPC title

• A61B5/1455

  using optical sensors, e.g. spectral photometrical oximeters · CPC title

• A61B5/0064

  Body surface scanning · CPC title

• A61B5/0059

  using light, e.g. diagnosis by transillumination, diascopy, fluorescence (photoacoustic A61B5/0093; optical measurement of heart rate A61B5/02416; optical measurement of blood flow A61B5/0261; optical measurement of analytes A61B5/1455) · CPC title

• A61B5/14532 Primary

  for measuring glucose, e.g. by tissue impedance measurement · CPC title