Laser device and method of transforming laser spectrum

Patent metadata

Field	Value
Publication number	US-11804694-B2
Application number	US-202016827095-A
Country	US
Kind code	B2
Filing date	Mar 23, 2020
Priority date	Mar 27, 2019
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

Provided are a laser device and a method of transforming laser spectrum, which provide a laser frequency stabilization and significant narrowing a laser spectrum. A laser device includes at least one multiple longitudinal mode laser (L) for generating a laser light having a spectrum of multiple longitudinal modes; at least one high quality factor (high-Q) microresonator (M) optically feedback coupled to the at least one multiple longitudinal mode laser (L); and a tuner (TU) for tuning the spectrum of multiple longitudinal modes of the laser light. The laser device is configured to output an output laser light having an output spectrum with at least one dominant longitudinal laser mode each at a reduced linewidth of the dominant longitudinal laser mode. The laser device allows increasing an emission power of a narrow linewidth lasing without an additional amplification while keeping a compact size of a device with a limited number of optical elements.

First claim

What is claimed is:

1. A laser device comprising:
at least one multiple longitudinal mode laser for generating a laser light having a spectrum of multiple longitudinal modes;
a plurality of high quality factor (high-Q) microresonators optically feedback coupled in parallel to the at least one multiple longitudinal mode laser; and
a tuner configured to tune the spectrum of multiple longitudinal modes of the laser light to match each of at least one frequency of an individual longitudinal mode of the at least one multiple longitudinal mode laser with a respective resonance frequency of the plurality of high-Q microresonators so as to obtain a plurality of matched frequencies,
wherein the laser device is configured to output an output laser light having an output spectrum with at least one dominant longitudinal laser mode and at a reduced linewidth of the dominant longitudinal laser mode, and wherein each of the at least one dominant longitudinal laser mode corresponds to one of the plurality of matched frequencies, and
wherein the plurality of high quality factor (high-Q) microresonators comprises:
a first high-Q microresonator configured to generate one counter-propagating mode; and
a second high-Q microresonator configured to generate two or more counter-propagating modes.

2. The laser device according to claim 1 ,
wherein the plurality of high-Q microresonators comprises a material having an intensity-dependent refraction index,
wherein the laser device is further configured to produce at least one optical frequency comb, and
wherein each of the at least one optical frequency comb is parametrically generated by one of the at least one dominant longitudinal laser mode, based on the at least one dominant longitudinal laser mode having a power above a pump threshold of an optical frequency comb generation.

3. The laser device according to claim 1 , wherein the tuner is configured to both change a spacing of the longitudinal modes at a frequency domain and change a frequency of each of the individual longitudinal modes of the at least one multiple longitudinal mode laser.

4. The laser device according to claim 1 , wherein the plurality of high-Q microresonators is configured to provide an optical feedback to the at least one multiple longitudinal mode laser by generating at least one counter-propagating mode each at one of the plurality of matched frequencies.

5. The laser device according to claim 1 , wherein the at least one multiple longitudinal mode laser includes an electrically powered semiconductor laser diode.

6. The laser device according to claim 1 , wherein the at least one multiple longitudinal mode laser and the plurality of high-Q microresonators are made on a same chip using microlithography.

7. The laser device according to claim 1 , wherein the tuner is further configured to control an injection current of the at least one multiple longitudinal mode laser or a temperature of a laser active medium of the at least one multiple longitudinal mode laser, or each of the at least one multiple longitudinal mode laser individually.

8. The laser device according to claim 1 , wherein the at least one multiple longitudinal mode laser is optically feedback coupled to the plurality of high-Q microresonators by coupling out a light scattered in the plurality of high-Q microresonators back to the at least one multiple longitudinal mode laser.

9. The laser device according to claim 1 , wherein at least one of the at least one multiple longitudinal mode laser is optically feedback coupled to one or several of the plurality of high-Q microresonators through a coupling element.

10. The laser device according to claim 9 , wherein the coupling element comprises at least one of a total internal reflection prism, a tapered optical fiber, and a waveguide.

11. The laser device according to claim 9 , wherein at least one of the plurality of high-Q microresonators is provided with an additional coupling element.

12. The laser device according to claim 11 , wherein the additional coupling element is configured to:
output at least one of the dominant longitudinal laser modes generated in the at least one of the plurality of high-Q microresonators or
output the at least one of the dominant longitudinal laser modes and at least one of optical frequency combs generated in the at least one of the plurality of high-Q microresonators to filter out a non-resonant part of the output spectrum.

13. The laser device according to claim 2 , wherein the at least one optical frequency comb is a dissipative Kerr soliton optical comb.

14. The laser device according to claim 1 , wherein the tuner is further configured to tune resonance frequencies of the high-Q modes of the plurality of high-Q microresonators by both changing a spacing of high-Q modes at a frequency domain and changing a resonance frequency of each of the high-Q modes.

15. The laser device according to claim 1 , wherein the tuner is configured to control a temperature of the plurality of high-Q microresonators or/and an external pressure applied to the plurality of high-Q microresonators, or each of the plurality of high-Q microresonators individually.

16. The laser device according to claim 1 ,
wherein the plurality of high-Q microresonators comprises an electro-optical material changing its refractive index in response to an electromagnetic field applied the plurality of high-Q microresonators, and
wherein the tuner is further configured to control the electromagnetic field applied to the plurality of high-Q microresonators, or each of the plurality of high-Q microresonators individually.

17. The laser device according to claim 1 , wherein the plurality of high-Q microresonators is a whispering-gallery modes (WGMs) microresonator.

18. A method of transforming a laser spectrum, the method comprising:
generating, by at least one multiple longitudinal mode laser, a laser light having a spectrum of multiple longitudinal modes;
tuning the spectrum of multiple longitudinal modes of the laser light to match each of at least one frequency of an individual longitudinal mode of the at least one multiple longitudinal mode laser with a respective resonance frequency of a plurality of high-Q microresonators optically feedback coupled in parallel to the at least one multiple longitudinal mode laser so as to obtain a plurality of matched frequencies; and
outputting an output laser light having an output spectrum with at least one dominant longitudinal laser mode and at a reduced linewidth of the dominant longitudinal laser mode, wherein each of the at least one dominant longitudinal laser mode corresponds to one of the plurality of matched frequencies,
wherein the method further comprises:
generating one counter-propagating mode by a first high-Q microresonator among the plurality of high quality factor (high-Q) microresonators, and
generating two or more counter-propagating modes by a second high-Q microresonator among the plurality of high quality factor (high-Q) microresonators.

19. The method according to claim 18 ,
wherein the plurality of high-Q microresonators comprises a material having an intensity-dependent refraction index, and
wherein the method further comprises parametrically generating at least one optical frequency comb by each of the at least one dominant longitudinal laser mode, based on the at least one dominant longitudinal laser mode having a power above a pump threshold of an optical frequency comb generation.

20. The method according to claim 18 , wh

Assignees

• Samsung Electronics Co Ltd
• International Center For Quantum Optics & Quantum Tech Limited Liability Company

Inventors

• Bilenko Igor Antonovich
• VASILIEV Vitali Valentinovich
• Voloshin Andrey Sergeevich
• Koptyaev Sergey Nikolaevich
• Lihachev Grigoriy Vasil'Evich
• Lobanov Valery Evgenievich
• Pavlov Nikolay Genad'Evich
• Polonsky Stanislav Vladimirovich
• Riabko Maxim Vladimirovich
• SHCHEKIN Alexey Andreevich

Classifications

• H01S5/1092 Primary

  Multi-wavelength lasing · CPC title

• H01S5/068

  Stabilisation of laser output parameters (H01S5/0625 takes precedence) · CPC title

• H01S5/0656 Primary

  Seeding, i.e. an additional light input is provided for controlling the laser modes, for example by back-reflecting light from an external optical component (H01S5/14, H01S5/4062 and H01S5/4006 take precedence) · CPC title

• H01S5/0657

  Mode locking, i.e. generation of pulses at a frequency corresponding to a roundtrip in the cavity · CPC title

• H01S5/06255

  Controlling the frequency of the radiation · CPC title