公开(公告)号：US20220131329A1

公开(公告)日：2022-04-28

申请号：US17427106

申请日：2019-10-28

Applicant: SOUTH CHINA UNIVERSITY OF TECHNOLOGY

Inventor： Shanhui XU ,  Kunyi LI ,  Changsheng YANG ,  Qilai ZHAO ,  Zhouming FENG ,  Zhongmin YANG

IPC: H01S3/067 ,  H01S3/11 ,  H01S3/04 ,  H01S3/10

Abstract: The invention discloses a multi-wavelength and single-frequency Q-switching optical fiber laser device. The laser device comprises a saturable absorber, a high gain optical fiber, a polarization-maintaining multi-wavelength narrow-band fiber Bragg grating, a resonant cavity temperature control module, a polarization-maintaining wavelength division multiplexer, a pump source and a polarization-maintaining light isolator. By taking a highly doped phosphate optical fiber as a laser gain medium, two ends of the optical fiber device are connected with the saturable absorber and the polarization-maintaining multi-wavelength narrow-band fiber Bragg grating respectively to form a short linear laser cavity. A short cavity length of the short linear laser cavity can realize single longitudinal mode operation of laser in the resonant cavity, and meanwhile, a stable multi-wavelength and single-frequency pulse laser output is realized in the resonant cavity by combining multi-wavelength resonance caused by the polarization-maintaining multi-wavelength narrow-band fiber Bragg grating with passive Q-switching performance of the saturable absorber in the cavity. The multi-wavelength single-frequency Q-switching optical fiber laser device of the invention realizes output of a plurality of wavelength pulse laser with adjusted repeated frequency simultaneously, and the laser in each wavelength is maintained in single-frequency operation, such that the multi-wavelength single-frequency Q-switching optical fiber laser device can be widely applied to aspects of laser radar, laser sensing, gas detection and the like.

公开(公告)号：US20220216666A1

公开(公告)日：2022-07-07

申请号：US17608482

申请日：2019-10-28

Applicant: SOUTH CHINA UNIVERSITY OF TECHNOLOGY

Inventor： Changsheng YANG ,  Shanhui XU ,  Linhuan HUANG ,  Zhongmin YANG ,  Zhouming FENG

IPC: H01S3/106 ,  H01S3/067

Abstract: Disclosed is a multimode interference effect-based wide tunable single-frequency optical fiber laser device. The laser device comprises a high-reflectivity chirped optical fiber grating, a high-gain optical fiber, a low-reflectivity chirped optical fiber grating, a pump source, an optical circulator, an optical fiber etalon and an SMS optical fiber structure apparatus. The high-reflectivity chirped optical fiber grating, the high-gain optical fiber and the low-reflectivity chirped optical fiber grating are connected in sequence to form a short linear resonant cavity; the optical circulator, the optical fiber etalon and the SMS optical fiber structure apparatus form a ring cavity, a stress loader is fixed onto the SMS optical fiber structure apparatus, and a transmitting wavelength of the SMS optical fiber structure apparatus is changed and tunable filtering by the SMS optical fiber structure apparatus is realized by loading stress to the SMS optical fiber structure apparatus.

公开(公告)号：US20210351558A1

公开(公告)日：2021-11-11

申请号：US17277305

申请日：2018-10-30

Applicant: SOUTH CHINA UNIVERSITY OF TECHNOLOGY

Inventor： Shanhui XU ,  Qilai ZHAO ,  Zhitao ZHANG ,  Changsheng YANG ,  Zhouming FENG ,  Zhongmin YANG

IPC: H01S3/13 ,  H01S3/067 ,  H01S3/0941 ,  H01S3/10 ,  H01S3/08 ,  H01S3/094 ,  H01S3/16

Abstract: A tunable narrow-linewidth photo-generated microwave source based on polarization control includes a high-reflectivity fiber grating, a high-gain fiber, a low-reflectivity polarization-maintaining fiber grating, a stress adjusting device, a single-mode semiconductor pump laser, an optical wavelength division multiplexer, a polarization beam splitter, a polarization controller, an optical coupler, and a photoelectric detector. Birefringence distribution in the low-reflectivity polarization-maintaining fiber grating is controlled by adjusting a stress magnitude of the stress adjusting device to the low-reflectivity polarization fiber grating, thereby controlling a laser frequency working in different polarization modes in a resonant cavity, and a tunable narrow-linewidth photo-generated microwave source is generated by a beat-frequency technology using a dual-wavelength narrow-linewidth laser with variable frequency intervals.

公开(公告)号：US20190252845A1

公开(公告)日：2019-08-15

申请号：US16343412

申请日：2016-12-19

Applicant: SOUTH CHINA UNIVERSITY OF TECHNOLOGY

Inventor： Shanhui XU ,  Zhongmin YANG ,  Yuning ZHANG ,  Zhouming FENG ,  Changsheng YANG

IPC: H01S3/08 ,  H01S3/067 ,  H01S3/0941 ,  H01S3/094 ,  G01S7/481

Abstract: A multi-wavelength single-frequency optical fiber laser source for a laser radar system includes a resonant cavity composed of a high-reflectivity chirped optical fiber grating, a high gain optical fiber and a low-reflectivity chirped optical fiber grating, a single-mode semiconductor pump laser served as a pump light source, an optical wavelength division multiplexer, an optical coupler, an optical isolator, an optical circulator, an optical filter module, and a semiconductor optical amplifier. The pump light source performs optical fiber core pumping with respect to the high gain optical fiber. A portion of the wide-spectrum laser is filtered by the optical filter module to obtain a wavelength corresponding to a specific central frequency. Multi-wavelength laser lasing with a narrow linewidth and single longitudinal mode is implemented by combining a short linear resonant cavity structure and the optical filter module.

公开(公告)号：US20180097332A1

公开(公告)日：2018-04-05

申请号：US15567082

申请日：2015-12-31

Applicant: SOUTH CHINA UNIVERSITY OF TECHNOLOGY

Inventor： Shanhui XU ,  Zhongmin YANG ,  Yuanfei ZHANG ,  Zhouming FENG ,  Changsheng YANG

IPC: H01S3/067 ,  H04B10/25 ,  H01S3/08

CPC classification number: H01S3/0675 ,  H01S3/08 ,  H01S3/094053 ,  H01S3/10023 ,  H01S3/10084 ,  H01S3/10092 ,  H01S3/105 ,  H04B10/25

Abstract: A width-tunable single-frequency fiber laser light source for coherent optical orthogonal frequency division multiplexing system including a chirped fiber grating with high reflectivity, a high gain optical fiber, a chirped fiber grating with low reflectivity, a single-mode semiconductor pump laser, an optical wavelength division multiplexer, an optical coupler, an optical circulator, and a tunable optical filter module is provided. The chirped fiber grating with low reflectivity and the chirped fiber grating with high reflectivity together serve as a front cavity mirror and a back cavity mirror of a resonant cavity to realize laser oscillation. After a laser with broad spectrum output from the optical wavelength division multiplexer is split by the optical coupler, a part of the laser passes through the optical circulator to enter the tunable optical filter module. A wavelength corresponding to any nominal center frequency stipulated by the ITU-T is selected by the tunable optical filter module, with a 3 dB spectral width of less than 0.1 nm, and is then injected back into the resonant cavity via the optical circulator and the optical coupler, and the resonant cavity is subjected to a self-injection locking.