Semiconductor laser module and Raman amplifier using the module

摘要

In a semiconductor laser module of the present invention, an FBG is disposed at the rear of a semiconductor laser device through a lensed fiber to define a cavity between the FBG and the semiconductor laser device. The reflectivity of an antireflection coating on a front end face of the semiconductor laser device is set to 1% or more, and the reflectivity of an antireflection coating on a rear end face of the semiconductor laser device is set to 0.5% or less. An isolator is disposed between a collimating lens and a condenser which are disposed in front of the semiconductor laser device. The FBG is formed in the lensed fiber. Two or more FBGs identical or different in the reflection center wavelength are disposed in the lensed fiber. The full width at half maximum of the FBG is set to 1 to 5 nm, and the reflectivity of the FBG is set to 50% or more. The semiconductor laser module is used in a Raman amplifier.