Investigation of Multiwavelength Performance based on different SOAs

Abstract

We investigated multiwavelength fiber laser (MWFL) performance using different types of semiconductor optical amplifiers (SOAs) utilizing Lyot filter as comb filter. The lasing performances of linear SOA (LSOA), nonlinear SOA (NLSOA) and booster optical amplifier (BOA) at different current settings were observed. Among the three SOAs, LSOA has the best lasing performance due to the lowest peak power difference with the highest number of lasing lines, a high ER value of 42 dB and considerable high peak power of -14.1 dBm at 550 mA. The multiwavelength laser is stable within 60 minutes at power fluctuation of less than 0.2 dB. The output spectra at 550 mA for all the SOAs are 70 nm to 80 nm wavelength difference from the ASE spectra.

Effect of Rayleigh backscattering on the multiwavelength random fiber laser bandwidth

“…The flatness of the lasing line is due to the combination of PC1 and PMF that act as a Lyot filter which provides complete constructive interference at a certain polarization angle [20]. This is possible due to the unique structure of PMF that allows light to travel inside the slow and fast axes before recombining in a linearly polarized light direction of 45°which defines the multiwavelength spectrum [2]. Any angle of PC1 that is out of 45°will affect the polarization state and cause destructive interference or a situation between constructive and destructive interference.…”

“…With a Lyot filter inside the ring cavity, the wavelength spacing of the multiwavelength spectrum can be calculated based on equation (1), whereby the λ represents the operating wavelength of the source. In contrast, B is the birefringence of the PMF (4 × 10 −4 ) and L is the length of the PMF [2].…”

“…The relative phase shift, j of the two beams of light traveling at the fast and the slow axes can be defined as [2]:…”

“…Multiwavelength fiber laser (MWFL) is widely used and has gained strong interest from many researchers due to its application in optical instrument testing, optical signal processing, and optical communication [1]. The main attraction of MWFL is its configuration of a simple and compact setup [2]. Multiwavelength random fiber laser (MWRFL) was proposed and implemented using photons that are distributed randomly inside a fiber cable and feedback in the form of Rayleigh backscattering (RBS) signals are amplified for laser production [3,4].…”