We present both design and experimental results for an As2S3 grating coupler on a thin film LiNbO3 substrate. A basic grating coupler structure is designed with coupling efficiency of 53% to a single mode fiber. A max...We present both design and experimental results for an As2S3 grating coupler on a thin film LiNbO3 substrate. A basic grating coupler structure is designed with coupling efficiency of 53% to a single mode fiber. A maximum simulated coupling efficiency of 78.8% is achieved, assuming a polymer bonding process. The basic structure was fabricated, and the coupling efficiency was measured to be at least 23.4% at 1540 nm. Some of the loss may be attributable to non-grating sources, such as waveguide tapers and testing fiber tails. A grating cavity was then measured using the grating couplers. The cavity waveguide propagation loss was 2.0 dB/cm. For a 400 nm thick As2S3 on 500 nm thin film LiNbO3 on insulator, the confinement factor in the LiNbO3 crystal is 82.3% when the As2S3 waveguide width is 400 nm, showing that As2S3-on-thin film LiNbO3 is an excellent candidate for thin film electro-optic applications.展开更多
A self-seeded fiber laser incorporated with a fiber Bragg grating external cavity semiconductor laser (FBG-ECL) and a Mach-Zehnder interferometer (MZI) were reported in this paper. The MZI provided a Q-switching with ...A self-seeded fiber laser incorporated with a fiber Bragg grating external cavity semiconductor laser (FBG-ECL) and a Mach-Zehnder interferometer (MZI) were reported in this paper. The MZI provided a Q-switching with response time in the order of micro-seconds. The FBG-ECL provided narrow pulses as seeds to shorten the Q-switched pulses. Experimentally, pulse width of 0.8 μs was measured, which was one fifth of the pulse width without self-seeding.展开更多
A full-open-cavity wavelength-tunable random fiber laser(WT-RFL) with compact structure and hundreds of picometers tuning range is proposed and demonstrated. A π fiber Bragg grating(FBG) is used in the WT-RFL as a fi...A full-open-cavity wavelength-tunable random fiber laser(WT-RFL) with compact structure and hundreds of picometers tuning range is proposed and demonstrated. A π fiber Bragg grating(FBG) is used in the WT-RFL as a filter to select lasing wavelengths. The two random Bragg grating arrays(RBGAs) and a section of high gain erbium-doped fiber result in a low lasing threshold and high stability. A numerical model to analyze the tunable characteristics is developed. The results show that the laser threshold is 22 m W, and the maximum peak-power fluctuation is 0.55 d B. To the best of our knowledge, it is the first time that a compact and full-open-cavity WT-RFL with two RBGAs and a π-FBG is proposed.展开更多
For different external cavity lengths, lasing wavelength variation of fiber grating external cavity semiconductor laser (FGECSL) with ambient temperature has been investigated theoretically, and the theoretical result...For different external cavity lengths, lasing wavelength variation of fiber grating external cavity semiconductor laser (FGECSL) with ambient temperature has been investigated theoretically, and the theoretical results are in agreement with reported experimental observations.展开更多
文摘We present both design and experimental results for an As2S3 grating coupler on a thin film LiNbO3 substrate. A basic grating coupler structure is designed with coupling efficiency of 53% to a single mode fiber. A maximum simulated coupling efficiency of 78.8% is achieved, assuming a polymer bonding process. The basic structure was fabricated, and the coupling efficiency was measured to be at least 23.4% at 1540 nm. Some of the loss may be attributable to non-grating sources, such as waveguide tapers and testing fiber tails. A grating cavity was then measured using the grating couplers. The cavity waveguide propagation loss was 2.0 dB/cm. For a 400 nm thick As2S3 on 500 nm thin film LiNbO3 on insulator, the confinement factor in the LiNbO3 crystal is 82.3% when the As2S3 waveguide width is 400 nm, showing that As2S3-on-thin film LiNbO3 is an excellent candidate for thin film electro-optic applications.
文摘A self-seeded fiber laser incorporated with a fiber Bragg grating external cavity semiconductor laser (FBG-ECL) and a Mach-Zehnder interferometer (MZI) were reported in this paper. The MZI provided a Q-switching with response time in the order of micro-seconds. The FBG-ECL provided narrow pulses as seeds to shorten the Q-switched pulses. Experimentally, pulse width of 0.8 μs was measured, which was one fifth of the pulse width without self-seeding.
基金supported by the National Natural Science Foundation of China (NSFC) (Nos. 61875185 and U1939207)the Scientific Instrument Developing Project of the Chinese Academy of Sciences+1 种基金the Strategic Priority Research Program A of the CAS (No. XDA22010201)the Shenzhen Science and Technology Research Funding (No. JCYJ20190814110601663)
文摘A full-open-cavity wavelength-tunable random fiber laser(WT-RFL) with compact structure and hundreds of picometers tuning range is proposed and demonstrated. A π fiber Bragg grating(FBG) is used in the WT-RFL as a filter to select lasing wavelengths. The two random Bragg grating arrays(RBGAs) and a section of high gain erbium-doped fiber result in a low lasing threshold and high stability. A numerical model to analyze the tunable characteristics is developed. The results show that the laser threshold is 22 m W, and the maximum peak-power fluctuation is 0.55 d B. To the best of our knowledge, it is the first time that a compact and full-open-cavity WT-RFL with two RBGAs and a π-FBG is proposed.
文摘For different external cavity lengths, lasing wavelength variation of fiber grating external cavity semiconductor laser (FGECSL) with ambient temperature has been investigated theoretically, and the theoretical results are in agreement with reported experimental observations.
