Design of Multiwavelength EDF-Raman Lasers Utilizing Mach-Zehnder Interferometer

Abstract

Abstract This paper presents the design of multiwavelength Erbium Doped Fiber (EDF)-Raman fiber laser utilizing Mach-Zehnder Interferometer (MZI) with various cavity structures. A multiwavelength laser employing hybrid gain medium of EDF-Raman amplifier is simulated using OptiSystem software. Three cavity structures of multiwavelength laser such as unidirectional, bidirectional and ring cavity are simulated and analysed. From the simulation result, it is found that ring cavity structure produced the best performance whereas at 1000 mW pump power, up to 19 lasing lines were obtained in the ring cavity, compared to 18, and 16 lasing lines in the unidirectional and bidirectional linear cavity, respectively. All multiwavelength fiber lasers exhibit the same line spacing of 4.9 nm. In addition, at coupling coefficient of 0.9, up to 49.5 dB of side mode suppression ratio (SMSR) were achieved in the ring cavity structure, compared to 49.2 dB, and 30.3 dB of SMSR in the unidirectional and bidirectional linear cavity, respectively. However, bidirectional linear cavity exhibits the highest peak power of 2.07 dBm, compared to -17.4 dBm, and -15.5 dBm of peak power in the unidirectional linear and ring cavity, respectively.