掺铒光纤上超短腔光纤激光器制作

We present an ultra-short distributed Bragg reflector fiber laser fabricated in erbium doped fiber. The total length of the laser is only 8 mm. The optical signal-to-noise ratio of the laser output is 50 dB. Due to the ultra-short cavity length, the laser has longitude mode spacing comparable to the grating bandwidth and therefore operates in robust single longitude mode. The laser emits two orthogonal polarization modes, which generates a beat signal at 1.12 GHz with 3-dB bandwidth of ~ 10 kHz. The peak absorption of the erbium doped fiber is 0.3 dB/cm at 980 nm. Including the loss of two splice points, an ultra-short DBR fiber laser has transmission loss at 980 nm of only 0.9 dB. This will greatly benefit the laser sensor multiplexing.