CN-122000783-A - Method and device for generating integrated key Shan Guzi microcavity optical frequency comb based on double-loop coupling system

CN122000783ACN 122000783 ACN122000783 ACN 122000783ACN-122000783-A

Abstract

The invention relates to a method and a device for generating an integrated key Shan Guzi microcavity optical frequency comb based on a double-loop coupling system, which comprise a III-V group pumping laser chip integrated in a single-chip manner, a double-coupling optical microcavity chip integrated in a silicon-based CMOS process, a temperature control unit, a driving control unit, an optical beam splitter, a detection unit, a photoelectric detector and a feedback control unit. According to the scheme, the generation of blue detuning of the single soliton microcavity optical frequency comb is realized through tuning local dispersion of the double-coupling microcavity. The technical scheme of the integrated key Shan Guzi microcavity optical frequency comb solves the problems of thermal instability, dependence on a high-quality factor micro-ring resonant cavity and relatively low output power of a microcavity Shan Guzi microcavity optical frequency comb caused by the fact that pump laser is required to be locked in microcavity red detuning during generation of a single soliton microcavity optical frequency comb in a single-cavity system, improves the system stability and reliability of the Shan Guzi microcavity optical frequency comb, and provides a feasible path for engineering application of the microcavity optical frequency comb in the fields of communication, sensing and the like.

Inventors

XIE PENG
WANG XINYU
Yi Shulan
HAN XILIN

Assignees

中国科学院上海光学精密机械研究所

Dates

Publication Date: 20260508
Application Date: 20260109

Claims (10)

1. The integrated key Shan Guzi micro-cavity optical frequency comb generating device based on the double-loop coupling system is characterized by comprising a single-chip integrated III-V group pumping laser chip, a silicon-based CMOS process integrated double-coupling optical micro-cavity chip, a temperature control unit, a driving control unit, an optical beam splitter, a detection unit, a photoelectric detector and a feedback control unit; the pump laser chip, the double-coupling optical microcavity chip, the optical beam splitter, the detection unit and the photoelectric detector are sequentially connected with the feedback control unit to form a closed-loop optical feedback control loop; The output end of the pump laser chip is coupled to the input end of the double-coupling optical microcavity chip; The double-coupling optical microcavity chip is used for regulating and controlling chromatic dispersion through a double-cavity coupling effect and generating a single soliton microcavity optical frequency comb, and the output end of the double-coupling optical microcavity chip is connected to the input end of the optical beam splitter; the temperature control unit is used for monitoring and controlling the temperature of the pump laser chip and the temperature of the double-coupling optical microcavity chip; The driving control unit is respectively connected with the pump laser chip and the double-coupling optical microcavity chip and is used for driving the pump laser chip and tuning the double-coupling optical microcavity chip; the input end of the optical beam splitter is optically connected to the optical frequency comb output end of the double-coupling optical microcavity chip, and divides input light into two paths, wherein one path serves as the main output of the device, and the other path is optically connected to the input end of the detection unit so as to provide feedback monitoring signals; the input end of the detection unit receives an optical frequency comb signal from the optical splitting path of the optical beam splitter and is used for monitoring the change of the center wavelength of the optical frequency comb, and the output end of the detection unit is connected to the input end of the photoelectric detector; the input end of the photoelectric detector is connected to the output end of the detection unit and is used for detecting the optical signal output by the detection unit, and the output end of the photoelectric detector is connected to the input end of the feedback control unit; The output end of the feedback control unit is connected to the pump laser chip and is used for adjusting the working current of the pump laser chip according to the electric signal output by the photoelectric detector.
2. The device according to claim 1, wherein the dual-coupling optical microcavity chip is of a through-type micro-ring structure and comprises a main cavity and an auxiliary cavity, the dual-cavity coupling is realized by optimizing the distance between the main cavity and the auxiliary cavity, and a certain deviation exists between the free spectral ranges of the main cavity and the auxiliary cavity; the main cavity is used for generating a single soliton microcavity optical frequency comb, and injection locking of narrow linewidth laser is required to be realized in a main cavity blue detuning region; The surface of the auxiliary cavity is provided with a metal film, and the driving control unit thermally tunes the metal film by applying tuning current to the metal film, so that the resonance state of the auxiliary cavity is changed to regulate and control the local dispersion of the main cavity.
3. The device of claim 2, wherein the metal film is made of titanium, platinum or gold.
4. The device of claim 2, wherein the ends of the input and output waveguides of the dual-coupling optical microcavity chip are provided with tapered structures or graded index lenses.
5. The apparatus of claim 1, wherein the pump laser chip is a distributed feedback laser chip or a reflective semiconductor optical amplifier chip, and an output end face thereof is coated with an antireflection film.
6. The apparatus of claim 1, wherein the pump laser chip and the dual-coupling optical microcavity chip are packaged by means of heterogeneous integration or optical gluing.
7. The apparatus of claim 1, wherein the temperature control unit comprises a temperature sensor.
8. The apparatus of claim 1, wherein the driving control unit is a multi-channel current source, one output channel of which is connected to the pumping laser chip to control a driving current thereof, and the other output channel of which is connected to the metal film of the auxiliary cavity to supply the tuning current.
9. The apparatus of claim 1, wherein the detection unit is a wavelength sensitive device, wherein the wavelength sensitive device is a fabry-perot cavity, an unequal arm mach-zehnder interferometer, or a phase shift grating.
10. The method for generating the integrated key Shan Guzi microcavity optical frequency comb based on the double-loop coupling system by adopting the device as claimed in any one of claims 1 to 9 is characterized in that the method for generating the integrated key Shan Guzi microcavity optical frequency comb comprises the following steps: S1, pump establishment and initial excitation, namely controlling the temperature control unit and the drive control unit to adjust and lock the output wavelength of the pump laser chip on a blue detuned resonance mode of the main cavity so as to excite an initial optical frequency comb in the main cavity; S2, tuning the resonance state of the auxiliary cavity through the driving control unit to enable the resonance state to be controllably coupled with the pumping mode of the main cavity so as to enhance the local anomalous dispersion of the main cavity, and enabling the optical frequency comb in the main cavity to be converted into a single soliton state; And S3, feedback locking and stable operation, namely starting the feedback control unit, monitoring the state of the output microcavity optical frequency comb through the detection unit and the photoelectric detector based on a feedback optical path signal separated by the optical beam splitter, feeding back a monitoring signal to the feedback control unit, and generating a control instruction according to the monitoring signal by the feedback control unit, and feeding back and adjusting the working current of the pump laser chip to realize automatic locking and long-term stable operation of the Shan Guzi microcavity optical frequency comb.

Description

Method and device for generating integrated key Shan Guzi microcavity optical frequency comb based on double-loop coupling system Technical Field The invention belongs to the technical field of integrated photonics and nonlinear optics, in particular relates to a method and a device for generating an integrated microcavity optical frequency comb, and particularly relates to a key-starting type Shan Guzi microcavity optical frequency comb generating method and device based on a double-ring coupling system. Technical Field The microcavity optical frequency comb is used as a frequency comb tooth coherent locking coherent light source excited in a semiconductor integrated microcavity, has the advantages of multiple wavelength channels, high coherence and the like, and has great application potential in a high-capacity information transmission and processing system compatible with a wavelength division multiplexing technology. Compared with a mode-locked laser optical frequency comb and an electro-optical frequency comb, the microcavity soliton optical frequency comb has the advantages of small size, easiness in integration, low power consumption, compatibility with a low phase noise and wavelength division multiplexing system and the like. With the development of artificial intelligence technology, a multi-wavelength light source compatible with a wavelength division multiplexing system is very important. The frequency interval of the microcavity soliton optical frequency comb is related to the radius of the microcavity, the frequency interval of the optical frequency comb can be compatible with a wavelength division multiplexing system by setting the radius of the microcavity, a coherent light source with hundreds of frequency intervals locked with each other can be provided, and the microcavity soliton optical frequency comb has important application prospects in various fields such as optical interconnection between future large-capacity optical communication and a data center. The Shan Guzi optical frequency comb in the anomalous dispersion region in the microcavity presents the characteristic of ultra-narrow pulse in the time domain, and can have important application value in the fields of precision measurement, on-chip optical clocks and the like. However, the generation of negative dispersion microcavity solitons still faces two key problems, namely 1. Low conversion efficiency. The quantum limit conversion efficiency in the traditional red detuning soliton scheme is only 3% -5%, the integral output power of the optical frequency comb is severely limited, the lower conversion efficiency of the optical frequency comb reduces the utilization value of the optical frequency comb, 2, the generation of the microcavity soliton optical frequency comb is in a red detuning state of a microcavity, the optical frequency comb is easy to be unlocked due to external noise such as power jitter and the like, and the stability of the generated microcavity optical frequency comb is reduced. Therefore, developing a microcavity Shan Guzi optical frequency comb with miniaturization, thermal stability and high conversion efficiency becomes a key for promoting the microcavity optical frequency comb engineering application. At present, a series of research methods are generated, and a series of research schemes such as an auxiliary mode, auxiliary laser, brillouin laser and the like are adopted in improving stability. The technical scheme (patent CN 111244741B) for assisting in photo-thermal balance is generally introduced to realize program control generation of single soliton, but the laser is generally required to be introduced into blue detuning of a microcavity through an acousto-optic modulator or additional pump laser, which increases complexity of a system, and in addition, generated single soliton optical frequency comb is still in red detuning, conversion efficiency is limited, and generation of single soliton in the microcavity still needs to undergo a complex evolution process. In addition, the introduction of modes such as an auxiliary mode and the like requires the specific design of the dispersion and mode coupling strength of the optical microcavity, so that the universality of microcavity soliton preparation is reduced. In terms of improving the conversion efficiency of the microcavity soliton, on the one hand, a soliton optical comb with a special form is adopted, such as a soliton crystal optical frequency comb, usually, the preparation of the soliton crystal optical frequency comb needs to additionally create a potential well field (Synthesized soliton crystals, nat Commun12, 3179 (2021)), which reduces the application value, and in addition, by creating corresponding mode frequency shift points, such as a photonic crystal cavity （Spontaneous pulse formation in edgeless photonic crystal resonators.Nat. Photon.15, 461–467 (2021).） and a double-cavity system （Surpassing the nonlinear conversion efficiency of s