IP Library Granted Patent US 12,388,230
Granted Patent B2
US 12,388,230 · App. 17/331,424 · Granted Aug 12, 2025

Monolithic photonic resonator and associated laser frequency stabilization method

Inventors: Wei Zhang (Boulder, CO); Liron Stern (Boulder, CO); Scott B. Papp (Boulder, CO)
Assignees: THE REGENTS OF THE UNIVERSITY OF COLORADO, A BODY CORPORATE; Government of the United States of America as represented by the Secretary of Commerce
H01S3/13H01S3/0407H01S3/061H01S3/1305
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Quick Facts
Patent No.
US 12,388,230
App. No.
17/331,424
Granted
Aug 12, 2025
Kind
B2
Abstract

A monolithic photonic resonator includes a bulk optic with first and second superpolished facets, and a high-reflectivity coating applied to each of the first and second superpolished facets. The superpolished facets form an optical resonator. The bulk optic is a single piece of an optical material that is solid, i.e., has no internal holes, gaps, or pockets. The bulk optic therefore serves as an intraresonator optical medium while still supporting a finesse of 10,000 or more. The superpolished facets may be counterfacing to form a Fabry-Perot cavity. Alternatively, the bulk optic may include forms one or more additional facets off of which light inside the bulk optic undergoes total internal reflection. The monolithic photonic resonator may be mounted in a support structure that minimizes the overall vibration sensitivity of the resonator's resonance frequency.

Claims (36)

1. A monolithic photonic resonator comprising:

a bulk optic with (i) one or more additional facets off of which light inside the bulk optic undergoes total internal reflection, (ii) a first and a second superpolished facet; and

a high-reflectivity coating applied to each of the first and the second superpolished facets;

wherein the first and second superpolished facets (i) form an optical resonator and (ii) cooperate with the one or more additional facets to define a mode structure of the optical resonator.

2. The monolithic photonic resonator of claim 1 , wherein the first and second superpolished facets are counterfacing such that the optical resonator is a Fabry-Perot cavity.

3. The monolithic photonic resonator of claim 2 , wherein:

the bulk optic is shaped as a solid cylinder; and

each of the first and second superpolished facets forms a circular end face of the solid cylinder.

4. The monolithic photonic resonator of claim 2 , wherein a distance between the first and second superpolished facets is between 5 and 100 mm.

5. The monolithic photonic resonator of claim 1 , wherein each of the first and second superpolished facets is planar.

6. The monolithic photonic resonator of claim 1 , wherein one or both the first and second superpolished facets is convex.

7. The monolithic photonic resonator of claim 1 , wherein the bulk optic is fabricated from one of: fused silica, sapphire, silicon, calcium fluoride, magnesium fluoride, terbium-doped calcium fluoride, terbium-doped fused silica, glass, and quartz.

8. The monolithic photonic resonator of claim 1 , wherein each high-reflectivity coating comprises an ion-beam sputtered dielectric stack.

9. The monolithic photonic resonator of claim 1 , wherein the first and second superpolished facets are co-planar.

10. The monolithic photonic resonator of claim 1 , at least one of the one or more additional facets being angled with respect to one or both of the first and second superpolished facets such that the optical resonator has a three-dimensional longitudinal mode structure.

11. The monolithic photonic resonator of claim 1 , each of the one or more additional facets being angled with respect to one or both of the first and second superpolished facets such that the optical resonator has a two-dimensional longitudinal mode structure.

12. A monolithic photonic resonator comprising:

a bulk optic with a first and a second superpolished facet; and

a high-reflectivity coating applied to each of the first and the second superpolished facets;

wherein the first and second superpolished facets form an optical resonator having a finesse of 10,000 or more at a wavelength between 1500 and 1600 nm.

13. A method for laser frequency stabilization, comprising:

coupling laser light into the monolithic photonic resonator of claim 12 ;

detecting light from the monolithic photonic resonator; and

locking, based on the detected light, a frequency of the laser light to a resonance of the monolithic photonic resonator.

14. A monolithic photonic resonator comprising:

a bulk optic with a first and a second superpolished facet that form an optical resonator;

a high-reflectivity coating applied to each of the first and the second superpolished facets; and

a support structure configured to receive the bulk optic, the support structure containing one or more support teeth that physically secure the bulk optic to the support structure.

15. The monolithic photonic resonator of claim 14 , wherein:

the bulk optic is shaped as a solid cylinder with a longitudinal optical axis;

the support structure is configured with a through-hole sized to receive the bulk optic; and

each of the one or more support teeth subtends an angle with respect to the longitudinal optical axis.

16. A method for laser frequency stabilization, comprising:

coupling laser light into the monolithic photonic resonator of claim 14 ;

detecting light from the monolithic photonic resonator; and

locking, based on the detected light, a frequency of the laser light to a resonance of the monolithic photonic resonator.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 9, 2025
From: ZHANG, WEI; STERN, LIRON
To: THE REGENTS OF THE UNIVERSITY OF COLORADO, A BODY CORPORATE
Reel/Frame 071648/0050 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 8, 2025
From: PAPP, SCOTT B.
To: GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE
Reel/Frame 071625/0614 →
CONFIRMATORY LICENSE Recorded Jun 22, 2021
From: UNIVERSITY OF COLORADO
To: U.S. DEPARTMENT OF ENERGY
Reel/Frame 056645/0875 →
Continuity (2)
Provisional Application 63030039 · May 26, 2020
Related Publication 20210376555A1 · Dec 2, 2021
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