Multiwavelength, bidirectional operation of twin-cavity Brillouin/erbium fiber laser

Multiwavelength twin-cavity Brillouin/erbium fiber laser (TBEFL) realizes bidirectional operation that could be used for dense wavelength division multiplexed (DWDM) system and fiber gyroscope. The TBEFL configuration consists of two identical erbium-doped fiber ring lasers (EDFL) that share a single mode fiber (SMF) to produce interdependent bi-directional Stokes signals. Launching the Brillouin pump (BP) into the SMF produced Stokes signal in the opposite direction and caused one ring to lase as a BEFL. The Stokes signal produced which is at 11 GHz Stokes shift frequency acts as a BP signal to the other end of the same SMF and generates the next Stokes in the opposite direction and resonates in the other ring. The operation of BEFL in the two rings sequentially iterates where Stokes signal produced is subservient to the previous signal. The twinning of the cavity in the BEFL system produces an 11-GHz (0.088 nm) comb of 24 channels at 1560 nm.