# US 11,909,165 B2 · Driven-cavity femtosecond sources

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,909,165 B2
- Document ID: US11909165B2
- Status: Granted
- Kind: B2
- Application number: 17/605,353
- Filed: 2020-04-21
- Published: 2022-06-16
- Granted: 2024-02-20
- Earliest claimed: 2019-04-25
- Assignees: University of Rochester
- Applicants: University of Rochester
- Inventors: William Renninger
- Web page: https://patentgrep.com/patent/US11909165B2

## CPC

- H01S 3/0057: {Temporal shaping, e.g. pulse compression, frequency chirping (soliton generation and propagation G02F1/3513, H01S3/063 and H01S3/108)}
- G02B 6/02214: {tailored to obtain the desired dispersion, e.g. dispersion shifted, dispersion flattened}
- G02B 6/2934: {Fibre ring resonators, e.g. fibre coils}
- H01S 3/0085: {Modulating the output, i.e. the laser beam is modulated outside the laser cavity}
- H01S 3/06725: {Fibre characterized by a specific dispersion, e.g. for pulse shaping in soliton lasers or for dispersion compensating [DCF]}
- H01S 3/06791: {Fibre ring lasers (fibre laser gyrometers G01C19/72)}
- H01S 3/1109: Active mode locking
- H01S 3/1303: {by using a passive reference, e.g. absorption cell (H01S3/139 takes precedence)}
- H01S 3/0078: {Frequency filtering}
- H01S 3/1305: {Feedback control systems}
- H01S 2301/085: solitons
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

Optical pulse sources. In one example, the pulse source includes an optical fiber ring resonator with at least one normal dispersion fiber segment characterized by a positive group velocity dispersion (GVD) per unit length and at least one anomalous dispersion fiber segment characterized by a negative GVD per unit length. In another example, the pulse source includes an optical fiber ring resonator with one or more fiber segments having a positive net group velocity dispersion (GVD); and an intracavity spectral filter optically coupled to the one or more fiber segments. The pulse source is configured to generate one or more optical solitons in the optical fiber ring resonator.

## Claims

### Claim 1

An optical pulse source comprising:
a drive unit configured to provide pump light at a drive power;
a passive optical fiber ring resonator optically coupled to the drive unit for receiving the pump light, the optical fiber ring resonator comprising:
at least one normal dispersion fiber segment characterized by a positive group velocity dispersion (GVD) per unit length; and
at least one anomalous dispersion fiber segment characterized by a negative GVD per unit length;
wherein the drive power, a net GVD of the optical fiber ring resonator, and a frequency detuning parameter of the optical fiber ring resonator are configured to generate one or more optical solitons in the optical fiber ring resonator, and wherein the one or more optical solitons each has a temporal duration from about 50 fs to about 500 fs, measured at full-width half-maximum; and
an output optically coupled to the optical fiber ring resonator for out-coupling a portion of each of the one or more optical solitons.

### Claim 2 (depends on 1)

The optical pulse source of claim 1, further comprising a feedback control circuit coupled to the drive unit and the optical fiber ring resonator, wherein the feedback control circuit is configured to cause a frequency of the pump light to be locked with respect to a resonance frequency of the optical fiber ring resonator.

### Claim 3 (depends on 1)

The optical pulse source of claim 1, further comprising a feedback control circuit coupled to the drive unit and the optical fiber ring resonator, wherein the feedback control circuit is configured to cause a resonance frequency of the optical fiber ring resonator to be locked with respect to a frequency of the pump light.

### Claim 4 (depends on 1)

The optical pulse source of claim 1, a length of the at least one normal dispersion fiber segment and a length of the at least one anomalous dispersion fiber segment are configured to provide the net GVD of the optical fiber ring resonator.

### Claim 5 (depends on 4)

The optical pulse source of claim 4, wherein the net GVD ranges from about −1000 fs2 to about −10,000 fs2.

### Claim 6 (depends on 1)

The optical pulse source of claim 1, wherein each of the one or more optical solitons has a full-width half-maximum temporal duration ranging from about 50 fs to about 210 fs.

### Claim 7 (depends on 1)

The optical pulse source of claim 1, wherein the optical fiber ring resonator further comprises an optical isolator.

### Claim 8 (depends on 7)

The optical pulse source of claim 7, wherein the optical isolator comprises an optical fiber isolator or a free-space isolator.

### Claim 9 (depends on 1)

The optical pulse source of claim 1, wherein the drive unit comprises a pump light source.

### Claim 10 (depends on 9)

The optical pulse source of claim 9, wherein the pump light source comprises a continuous-wave (CW) laser source.

### Claim 11 (depends on 9)

The optical pulse source of claim 9, the drive unit further comprises an optical amplifier configured to amplify optically coupled to the pump light source.

### Claim 12 (depends on 11)

The optical pulse source of claim 11, wherein the optical amplifier comprises an erbium-doped fiber amplifier (EDFA).

### Claim 13 (depends on 9)

The optical pulse source of claim 9, wherein the drive unit further comprises an intensity modulator optically coupled to the pump light source and configured to modulate an intensity of the pump light into a pulse train.

### Claim 14 (depends on 13)

The optical pulse source of claim 13, further comprising a spectral filter optically coupled to the output.

### Claim 15 (depends on 14)

The optical pulse source of claim 14, wherein the spectral filter comprises a fiber Bragg grating (FBG), or a birefringence-based spectral filter, or an interference-based spectral filter.

### Claim 16 (depends on 1)

The optical pulse source of claim 1, wherein the optical fiber ring resonator comprises at least one free-space air gap.

### Claim 17 (depends on 1)

The optical pulse source of claim 1, wherein the at least one normal dispersion fiber segment and the at least one anomalous dispersion fiber segment comprise polarization-maintaining optical fibers.

### Claim 18 (depends on 1)

The optical pulse source of claim 1, further comprising an optical compression component coupled to the output and configured to compress the portion of each of the one or more optical solitons temporally.

### Claim 19 (depends on 18)

The optical pulse source of claim 18, wherein the optical compression component comprises a pair of gratings, or a pair of prisms, or an optical fiber compression component.

### Claim 20 (depends on 1)

The optical pulse source of claim 1, wherein the negative GVD per unit length of the at least one anomalous dispersion fiber segment ranges from about −1000 fs2 to −50,000 fs2, or from about −1000 fs2 to −10,000 fs2, or from about −1000 fs2 to −5,000 fs2.

### Claim 21 (depends on 1)

The optical pulse source of claim 1, wherein the drive power ranges from about 10 mW to about 1 kW.

### Claim 22 (depends on 1)

The optical pulse source of claim 1, wherein the frequency detuning parameter ranges from about −0.5 radians to about −3 radians per roundtrip.