Multiwavelength Random Fiber Laser based on Bidirectional SOA and Lyot filter

We investigated the performance of multiwavelength random fiber laser (MWRFL) using a bidirectional semiconductor optical amplifier (SOA) and Lyot filter inside a ring cavity. The bidirectional nature of linear SOA acts as the gain medium while the Lyot filter functions as the wavelength-selective device. The input SOA current, half-wave plate (HWP) angles of polarization controllers (PCs), and the stability of the laser were measured to determine the best optimized lasing line. The best MWRFL performance of 57 lasing lines within the 5 dB spectral range, 27.5 dB extinction ratio (ER), and 11.4 nm multiwavelength bandwidth are achieved through 550 mA of SOA current. The HWP angles of 90° and 120° for PC1 and PC2 respectively aid in the best polarization state of the output spectrum compared to other HWP angles measured at every interval of 30°. The laser had good stability with a maximum peak value deviation of 0.35 dBm at a wavelength range from 1541.0 nm to 1549.0 nm.