Multiwavelength Random Fibre Laser with Highly Nonlinear Fibre as Gain Medium

• Main Author: Durkasiny Ramachandran
• Language: English
• Published: 2023
• Subjects: Multiwavelength Fibre Laser; Semiconductor Optical Amplifier; Erbium Doped Fibre Amplifier; Lyot Filter

ABSTRACT In the past years, the multiwavelength fibre laser has been an interesting research topic because of its great benefits in the field of optical Fibre sensing in Photonics network. This thesis investigates the performance of multiwavelength fibre laser (MWFL) laser output based on highly nonlinear fibre (HNLF) by inducing nonlinear effect which is four-wave mixing (FWM) to suppress the homogeneous broadening caused by erbium-doped fibre amplifier (EDFA). The multiwavelength fibre laser is generated by the utilising semiconductor optical amplifier (SOA) and EDFA as the gain media. A nonlinear polarization rotation effect (NPR) is induced from the combination of SOA and polariser in the linear cavity. IDL Mechanism has been utilised to generate stable and flat MWFL. The optical signal to noise ratio (OSNR) is obtained below 20 dB due to the length of the polarisation maintaining fibre (PMF). In addition, adjustments of SOA current and polarisation controller (PC) angle are found to contribute to obtaining a flat and wider bandwidth multiwavelength spectrum. The proposed MWFL design is flat, more wavelength lines and wider bandwidth.