Effective use of an EDFA and Raman pump residual powers via a Bi-EDF in L-band multi-wavelength fiber laser generation

Abstract

Residual powers of an erbium-doped fiber amplifier (EDFA) and a Raman pump are utilized effectively for pumping a 0.45 m long bismuth-based EDF (Bi-EDF) in linear-cavity L-band multi-wavelength fiber laser generation. A 7.7 km dispersion compensating fiber (DCF) operates as both Brillouin and Raman gain media and a 6.5 dBm fixed-power tunable laser source (TLS) amplified by an EDFA works as a Brillouin pump (BP). By inserting the Bi-EDF in the linear cavity and using the EDFA and the fixed Raman pump residual powers 13.6 mW and 64 mW, at wavelengths 978.8 nm and 1490.6 nm respectively, the gain spectrum is inhomogeneously broadened so that linewidth of the gain spectrum is expanded from 3.4 to 12.3 nm. As a result, the number of lines of an L-band multi-wavelength fiber laser (MFL) is increased noticeably. In addition, the number of lines at a BP wavelength 1590.6 nm decreased from 38 to 32 by using the maximum EDFA pump residual power of 44 mW due to a reduction in the quantum coefficient efficiency. However, flatness and stability characteristics of the MFL are improved. The MFL can be generated in the wavelength region 1570–1610 nm with the signal to noise ratio of about 42.