We demonstrated an all-fiber single-frequency DBR master oscillator and power amplifier at 1992.6 nm. The maximum output power of the fiber amplifier was 100 W with a slope efficiency of 53% and the optical signal-to-noise ratio was about 50dB. The linewidth was less than 66 kHz and the beam quality factor M<sup>2</sup> was 1.22 at the maximum output power. The RINs of the seed and the power amplifier were measured to be -120 dB/Hz and -102 dB/Hz at the relaxation oscillation frequency, respectively.
Frequency swept laser sources have various applications, such as LIDAR, spectroscopy, sensing. We demonstrate a 1.5-μm frequency-sweepable single frequency fiber laser in this work. By modulating the intensity of the pump, photo-induced refractive index change occurs in the gain fiber and the free spectral range of the laser is improved. As a result, the frequency sweeping can be realized. The DBR structure is employed to ensure the single-frequency operation. The central wavelength and the maximum sweeping range is measured to be 1550.25nm and 800MHz, respectively. A repetition rate up to 1kHz with an average output power of 0.6mw is realized.
Proc. SPIE. 9728, Fiber Lasers XIII: Technology, Systems, and Applications
KEYWORDS: Fiber lasers, Signal to noise ratio, High power lasers, Optical isolators, Laser applications, Acoustics, High power fiber amplifiers, Optical amplifiers, Laser damage threshold, Polarization
We demonstrate a high-power, high signal-to-noise ratio single-frequency 1 μm Brillouin all-fiber laser with high slope efficiency. The Brillouin laser system consists of a high-power single-frequency fiber laser and a single-pass Brillouin ring cavity. The high-power single-frequency fiber laser is one-stage master-oscillator power amplifier with the maximum output power of 10.33 W, the signal-to-noise ratio of 50 dB and the slope efficiency of 46%. The Brillouin fiber laser is pumped by the amplified laser with a linewidth of 33 kHz and an output power of 2.61 W limited by the damage threshold of the optical isolator. By optimizing the length of the Brillouin ring cavity to 10 m, stable singlefrequency Brillouin fiber laser is obtained with 3 kHz linewidth owing to the linewidth narrowing effect. At the launched pump power of 2.15 W, the Brillouin fiber laser generates maximum output power of 1.4 W with a slope efficiency of 79% and the optical signal-to-noise ratio of 77 dB.