| 摘要 |
PURPOSE:To amplify light efficiently over a wide band, by using a double refraction optical fiber as an optical fiber, and changing the stress of the optical fiber from the external by a stress changing means in accordance with the wavelength of signal light to be amplified. CONSTITUTION:An optical fiber type light amplifying element using four-optical element mixing due to the tertiary non-linear polarization effect of an optical fiber uses the double refraction optical fiber 23 as the optical fiber and changes the stress of the optical fiber 23 from the external through a stress applying device 24 in accordance with the wavelength of a signal to be amplified which is outputted from a signal light source 14. When it is defined that pump light from a pump light source 11, signal light from the signal light source 14 and the phase constant of idler light in the optical fiber 23 are KP, KS and KAS, the phase matching condition 2KP=KS+KAS is formed and the signal light is amplified. |
