摘要 |
<p>A dual-wavelength pumped low noise fiber laser includes a fiber laser (10) comprising a pair of Bragg gratings (14, 16) at opposite ends of a fiber laser cavity (18) which is co-doped with two rare-earth dopants, Er<+3>Yb<+3>, so as to allow lasing to occur at a lasing wavelength lambda L. A first pump signal (20) efficiently pumps the Yb to the excited state and the Yb energy is transitioned to the Er atoms which ultimately lase at the desire lasing frequency. Because Yb is pumped so efficiently, high pump absorption is achieved, thereby providing high laser output power and, consequently, reduced RIN. Simultaneously, a second pump signal (52) directly pumps the Er at a different wavelength lambda P2 which populates the lasing transition more quickly, thereby allowing sufficient bandwidth of a closed loop control on the second pump signal (52) to control low frequency RIN spiking due to relaxation oscillations in the laser.</p> |