Ultra Low-noise Single-Frequency Narrow Linewidth Fiber Laser Technology
September 7, 2016, hosted by OFweek Chinese high-tech industry portals, network host OFweek laser, the laser industry in Hubei Province Association of the "OFweek 2016 China advanced laser technology and application seminar" was held in the Sheraton Grand Hotel Shenzhen · China. Zhang Rui, general manager of the new Shanghai Hanyu Optical Fiber Communication Technology Co., Ltd. in this meeting published the "ultra low noise single-frequency narrow linewidth fiber 30000mw laser pointertechnology and application," keynote speech, focusing on the commercial single-frequency fiber laser key technology and products to interpret .
According to Zhang Rui new introduction: "At present, in the commercial area of single-frequency fiber laser technology is mainly divided into the following four categories: 1 short straight single-frequency DFB fiber laser cavity; 2 straight short cavity DBR type; 3 complex chamber technology; 4 and the annular chamber composite technology annular cavity.
Four technologies have advantages and disadvantages, such as the advantages of short straight single-frequency DFB fiber laser cavity is a simple resonator structure, FSR up to GHz, easy to implement single-longitudinal-mode output. The disadvantage is that the 1/4 wavelength phase-shift fiber grating requires high technical difficulty, the doped fiber doping concentration between the noise and the need for balanced consideration of fiber green laser pointer, fiber grating wavelength special difficulties, the noise is too large and so on. Straight and short cavity DBR type, although with high gain, can achieve higher power output and easy to implement single-longitudinal-mode output, etc., but also difficult to achieve with a strong weld, poor reliability cavity for frequency selection grating requirements more high, not easy to achieve, short straight cavity difficult to produce, difficult to adapt to the harsh working conditions and other shortcomings.
With respect to the above techniques, Shanghai Hanyu CoSF-1 single-frequency fiber laser is through "optimized traveling wave cavity" design eliminates standing waves spatial hole burning effects. Meanwhile, long cavity length is designed to allow a longer gain fiber, fully absorb the pump light, high power output; traveling wave operation significantly reduced relative intensity noise and phase noise fiber lasers. And all-fiber injection narrowband filter to select a single longitudinal mode output; long saturable absorber stable single longitudinal mode operation; single polarization control eliminates polarization hole burning, stable single polarization output polarization extinction ratio of up to 25dB or more. Phase noise, key indicators frequency noise, line width, frequency stability and power stability have reached a higher level.
Finally, the new Zhang Rui said: "The future of Shanghai Hanyu will launch the second generation CoSF-2 single-frequency fiber lasers and third generation CoSF-3 single-frequency fiber lasers in which the second-generation CoSF-2 single-frequency fiber burning laser pointer will be used injection /. filtering technology to further narrow linewidth pressure, reduce noise, while also using passive frequency stabilization technology, RIN suppression technology, PZT FM technology and optimization of packaging technology to enhance the resistance to vibration, impact resistance, harsh environment. the third-generation CoSF -3 single-frequency fiber laser frequency stabilization technology will be used to lock, toward miniaturization, multi-channel integration direction. "