A Nd(3+)-doped cw fiber laser using all-fiber reflectors

We demonstrate a novel all-fiber resonant optical cavity which uses two-fiber reflectors, each formed by a single loop of fiber between the output ports of a fiber directional coupler. The reflectivities of the fiber mirrors are each determined by the coupling ratio and the insertion loss of the fused couplers. When the cavity is formed in this way using a continuous length of Nd(3+)-doped fiber and pumped using a GaAs laser diode, lasing occurs at a wavelength of 1064 nm. Both theoretical and practical descriptions of the device are given.