Patent ID: 7940454

Claim:
An optical parametric amplifier provided with a nonlinear optical medium to which is input signal light and pumping light, which amplifies the signal light by an optical parametric amplification effect due to the pumping light, and outputs this, said optical parametric amplifier comprising: a signal light input port to which is input said signal light; a pumping light input port to which is input said pumping light for which the wavelength is different to that of said signal light; a first optical amplifying section which has an amplification band which includes the wavelength of said pumping light and doesn't include the wavelength of said signal light, and which amplifies said pumping light input to said pumping light input port, and outputs this; and a pumping light supply section which supplies said pumping light output from said first optical amplifying section, together with said signal light input to said signal light input port and having a wavelength outside the amplification band of said first optical amplifying section, to said nonlinear optical medium, wherein said first optical amplifying section is constructed using an erbium doped fiber amplifier having an amplification band in a C-band, said pumping light has a wavelength close to the edge on the short wavelength side in the C-band, and said nonlinear optical medium amplifies signal light having a wavelength in a region on the short wavelength side from the C-band, by an optical parametric amplification effect due to said pumping light, and outputs this.