Patent ID: 6317253
Filing Date: 2001-11-13
Classification: H01S

Abstract:
An optical amplifier apparatus comprising:first optical isolator means for making an incident signal light having wavelengths within the 1.06 .mu.m band pass therethrough in one direction from an input end thereof to an output end thereof, and outputting the signal light;an optical fiber including a core mainly composed of silica glass and doped with Nd and Al, and a cladding of silica glass, said optical fiber transferring in a single mode the signal light output from said first optical isolator means;excitation light source means for generating excitation light having an excitation wavelength of 0.8 .mu.m band;optical multiplexer means for multiplexing the excitation light generated by said excitation light source with signal light transferred by said optical fiber, by outputting the excitation light generated by said excitation light source to said optical fiber, and for transferring and outputting the signal light having wavelengths of 1.06 .mu.m band amplified by induced emission in said optical fiber due to the Nd excited by the excitation light; andsecond optical isolator means for making the signal light output from said optical multiplexer means pass therethrough in one direction from an input end thereof to an output end thereof, and outputting the signal light as amplified signal light, wherein said core of said optical fiber is sufficiently doped with Al to thereby provide an increased available doping density of Nd, resulting in increased amplification of the signal light.