Single-Frequency Linearly-Polarization Q-Switched Nanosecond Fiber Ring-Cavity Laser Enabled by an Electro-Optic Modulator

We report a single-frequency linearly-polarized nanosecond fiber ring-cavity laser based on an electro-optic modulator. A 0.08-nm-bandwidth Bragg grating combined with section of 1-m unpumped Yb-doped act as ultra-narrow bandwidth filter to realize output. The devices used in the experiments are all polarization-maintaining ensure Pulsed is obtained by using modulator adjust loss cavity periodically. And repetition rate pulse trains can be flexibly changed from 550 1000 kHz width 27–59 ns. By varying amplitude arbitrary function generator, we pulsed output 51–493 linewidth 31.8 MHz, and polarization extinction ratio was better than 20 dB.