# US 2020/0401013 A1 · Multiple kerr-frequency-comb generation using different lines from a remote kerr comb

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- Number: US 2020/0401013 A1
- Document ID: US20200401013A1
- Status: Published application
- Kind: A1
- Application number: 16/979,153
- Filed: 2019-03-07
- Published: 2020-12-24
- Earliest claimed: 2018-03-09
- Assignees: University of Southern California
- Applicants: University of Southern California
- Inventors: Peicheng Liao; Alan Willner; Ahmed Almaiman; Changjing Bao
- Web page: https://patentgrep.com/patent/US20200401013A1

## CPC

- G02F 1/365: in an optical waveguide structure (G02F1/377, {G02F1/395} take precedence)
- H04B 10/508: Pulse generation, e.g. generation of solitons
- G02F 1/3511: {Self-focusing or self-trapping of light; Light-induced birefringence; Induced optical Kerr-effect}
- G02F 2203/56: Frequency comb synthesizer
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- H04B: TRANSMISSION

## Abstract

Methods, systems, and apparatus for generating Kerr frequency combs. The system includes a continuous-wave pump laser to provide a master comb pump. The system includes a microresonator that generates a master Kerr frequency comb using the master comb pump. The system includes a splitter that splits the master Kerr frequency comb into multiple CW comb lines including a first comb line used to transmit a data signal and a second comb line used as a slave comb pump. The system includes a combiner that is configured to combine the first comb line and the second comb line to produce a combination of a data channel and CW comb line. The system includes a second demultiplexer that extracts the second comb line that is used as the slave comb pump. The system includes another microresonator that uses the second comb line and generates a slave Kerr frequency comb.

## Claims

### Claim 1

A communication system for generating multiple Kerr frequency combs, comprising:
a continuous-wave (CW) pump laser configured to provide a master signal;
a master microresonator configured to generate a master Kerr frequency comb using the master signal;
a splitter configured to split the master Kerr frequency comb into a first comb line used to transmit a data signal and a second comb line used as a slave signal; and
a combiner or multiplexer configured to combine the first comb line carrying signal and the second comb line to produce a combined signal.

### Claim 2 (depends on 1)

The communication system of claim 1, wherein the master signal is a master comb pump and the slave signal is a slave comb pump.

### Claim 3 (depends on 2)

The communication system of claim 2, further comprising:
a first demultiplexer configured to receive the combined signal and extract the second comb line that is used as the slave comb pump; and
a slave microresonator configured to generate a slave Kerr frequency comb from the second comb line.

### Claim 4 (depends on 3)

The communication system of claim 3, further comprising:
a demodulator connected to the slave microresonator and configured to:
receive the generated slave Kerr frequency comb,
mix the generated slave Kerr frequency comb with the data signal on the first comb line to demodulate the data signal, and
output the demodulated data signal that has reduced phase noise.

### Claim 5 (depends on 2)

The communication system of claim 2, wherein the splitter forms a third comb line used to transmit a second data signal and a fourth comb line used as a second slave comb pump.

### Claim 6 (depends on 5)

The communication system of claim 5, further comprising:
a second combiner that is configured to combine the third comb line and the fourth comb line to form a second combined signal;
a second splitter that is configured to extract the fourth comb line that is used as the second slave comb pump; and
a second slave microresonator configured to receive the fourth comb line and use the fourth comb line as the second slave comb pump to generate a second slave Kerr frequency comb.

### Claim 7

A communication system for generating multiple Kerr frequency combs, comprising:
a first microresonator connected to a laser controlled by an arbitrary function generator to generate a master Kerr frequency comb;
a first demultiplexer coupled to the first microresonator and configured to split the master Kerr frequency comb onto a first comb line with a slave comb pump and a second comb line with a data signal; and
a combiner configured to transmit a combined slave comb pump and data signal.

### Claim 8 (depends on 7)

The communication system of claim 7, further comprising:
a second demultiplexer configured to receive the combined slave comb pump and data signal and extract the slave comb pump onto a first comb line and the data signal onto a second comb line;
a second microresonator configured to generate a slave Kerr frequency comb from the slave comb pump; and
a photodetector connected to the second microresonator and configured to output a demodulated signal using the generated slave Kerr frequency comb and the data signal.

### Claim 9 (depends on 8)

The communication system of claim 8, wherein the first demultiplexer is an array waveguide grating or a tunable fiber Bragg grating.

### Claim 10 (depends on 8)

The communication system of claim 8, wherein slave Kerr frequency comb is mutually coherent with the master Kerr frequency comb.

### Claim 11 (depends on 7)

The communication system of claim 7, wherein the first demultiplexer is further configured to split the master Kerr frequency comb onto a third comb line and a fourth comb line, wherein the third comb line has a second slave comb pump and the fourth comb line has a second data signal.

### Claim 12 (depends on 11)

The communication system of claim 11, further comprising:
a second combiner configured to:
combine the second slave comb pump with the second data signal to form a second combined signal, and
transmit the combined slave comb pump and the second data signal.

### Claim 13 (depends on 11)

The communication system of claim 11, further comprising:
a third demultiplexer configured to receive the second combined signal and select or extract the second slave comb pump from the second combined signal; and
a third microresonator configured generate a second slave Kerr frequency comb from the second slave comb pump.

### Claim 14

A method of generating multiple Kerr frequency combs, comprising:
generating, using a first microresonator, a master Kerr frequency comb using a master signal;
splitting or demultiplexing, using a splitter or demultiplexer, the master Kerr frequency comb into a first data signal, a first slave signal, a second data signal and a second slave signal;
combining, using a first combiner, the first data signal and the first slave signal into a first combined signal;
combining, using a second combiner, the second data signal and the second slave signal into a second combined signal; and
transmitting, using the first combiner and the second combiner, the first combined signal to a first receiver and the second combined signal to a second receiver.

### Claim 15 (depends on 14)

The method of claim 14, comprising:
extracting the first data signal and the first slave signal from the first combined signal; and
extracting the second data signal and the second slave signal from the second combined signal.

### Claim 16 (depends on 15)

The method of claim 15, further comprising:
generating a slave Kerr frequency comb from the first slave signal;
demodulating the first data signal using the slave Kerr frequency comb; and
outputting the demodulated signal.

### Claim 17 (depends on 16)

The method of claim 16, wherein demodulating the first data signal using the slave Kerr frequency comb includes mixing the generated slave Kerr frequency comb with the first data signal.

### Claim 18 (depends on 17)

The method of claim 17, wherein the outputted demodulated signal has reduced noise.

### Claim 19 (depends on 14)

The method of claim 14, wherein the first combined signal is transmitted to the first receiver across a first single mode fiber and the second combined signal is transmitted to the second receiver across a second single mode fiber.

### Claim 20 (depends on 14)

The method of claim 14, wherein generating the master Kerr frequency comb includes controlling a wavelength of the master comb pump using an arbitrary function generator.