Space-tunable optical frequency comb based on phase modulation and fiber cavity solitons and its generation method

Abstract

The invention relates to the technical field of nonlinearity optical fiber optics, in particular to an alternately adjustable optical frequency comb based on phase modulation and optical fiber cavitysoliton and a generation method thereof. The optical frequency comb is composed of a narrow-linewidth tunable laser, a phase modulator, a variable-gain erbium-doped fiber amplifier, a narrow-band fiber filter, a polarization controller, a first optical fiber coupler, an optoisolator, a second optical fiber coupler, a main fiber, a variable optical attenuator, a first photoelectric detector, a laser frequency locking system, a second photoelectric detector, a high-speed oscilloscope, a data storage and processing system, a pulse-pattern generator and an electricity amplifier. The provided alternately adjustable optical frequency comb based on the phase modulation and the optical fiber cavity soliton and the generation method thereof have the advantages that only a common single mode fiber is needed to form an annular cavity, the generated optical frequency comb has low noise and high coherence, and is especially suitable for being used as a light source of a system very sensitive to phase noise such as a large-scale interference type optical sensing system.

Description

technical field [0001] The invention relates to the technical field of nonlinear fiber optics, in particular to a space-adjustable optical frequency comb based on phase modulation and fiber cavity solitons and a generation method. Background technique [0002] An optical frequency comb is a comb-like structure composed of several single-frequency lights with the same frequency interval. It has been widely used in optical communication, arbitrary waveform generation, microwave photonics and other fields. The outstanding advantage of flexible setting according to actual needs can be used as a light source for large-scale optical fiber communication systems or optical fiber sensing systems, which has attracted widespread attention. [0003] In recent years, various methods have been used to produce optical frequency combs with adjustable frequency intervals. Chinese invention patent application "A Tunable Optical Frequency Comb Generation System Based on Monolithic Integrated ...

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Problems solved by technology

Chinese invention patent application "A Tunable Optical Frequency Comb Generation System Based on Monolithic Integrated Microcavity Laser" (Application No.: 201510169696.5, Publication Date: 2015.07.08) uses the cascaded four-wave mixing effect of optical fibers to generate an optical frequency comb, Need to use more expensive high nonlinear fiber; Chinese invention patent application "Tunable Optical Frequency Comb Based on Dual-mode Square Microcavity Laser" (application number: 201510166090.6, publication date: 2015.07.08) also requires the level of high nonlinear fiber The combined four-wave mixing effect produces an optical frequency comb, and it only realizes dual-mode lasers, and the efficiency is low; China's invention patent application "An Optical Frequency Reference Fiber Femtosecond Optical Frequency Comb with Repetition Frequency Tunable Broadband" (Application No. : 201610366387.1, public date: 2016.08.03) The generation of optical frequency combs requires the use of broadband tunable erbium-doped fiber femtosecond lasers based on hybrid mode-locked repetition rates, and requires the use of fast and slow piezoelectric ceramics and pump current modulation Coordinated control of the beat frequency of femtosecond lasers and two reference lasers is more complicated to implement; Chinese invention patent application "A Wide and Flat Tunable Optical Frequency Comb Generation Method" (application number: 201610031924.7, publication date: 2016.06.01 The generation of optical frequency combs in ) requires the use of two tunable light sources and dual-drive Mach-Zehnder modulators, which is also relatively complicated to implement; the Chinese invention patent application "A Repetition Frequency Tunable Optical Frequency Comb Based on Optical Feedback" ( Application number: 201611103512.6, publication date: 2017.03.15) and utility model patent "An Optical Frequency Comb with Adjustable Repetition Frequency Based on Optical Feedback" (ZL201621323117.4) When generating an optical frequency comb, it is necessary to use an adjustable laser delay module to Single-frequency laser performs delay processing, and at the same time combines high-stable signal source, error signal processing system and laser frequency modulation device to realize laser frequency locking; Chinese invention patent "high stability, large frequency interval, frequency interval adjustable optical frequency comb" (ZL201310128950 .8) Although a tunable optical frequency comb is generated within a large frequency interval, it is necessary to select an appropriate modulation depth based on the analysis of the signal-to-noise ratio; Chinese invention patent "A Method for Generating a Tunable Optical Frequency Comb" (ZL201310567253. 2) The optical frequency comb is realized by cascading optical intensity modulators, but it needs to adjust multiple radio frequency amplitudes and DC bias voltage parameters at the same time, and its frequency interval adjustment is limited

[0004] In short, although there are many methods for generating frequency-spacing tunable optical frequency combs, most of them are based on traditional modulator cascade or nonlinear four-wave mixing effect. Optical frequency comb adjustment methods and device structures are often complicated, and sometimes It is also necessary to use more expensive highly nonlinear fibers to enhance the four-wave mixing effect

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