Optical amplifier

An optical receiver comprising:

• a phase sensitive amplifier that amplifies signal light based on the optical mixing using a nonlinear optical effect, the phase sensitive amplifier comprising:
• an optical fiber laser amplifier for amplifying fundamental wave light;
• a second-order nonlinear optical element that consists of a periodically-poled second-order nonlinear optical material and that includes an optical waveguide for generating a sum frequency light from fundamental wave light;
• a filter for separating the sum frequency light from among the fundamental wave light and the sum frequency light;
• a multiplexer for multiplexing the signal light and the sum frequency light that is pump light;
• a second-order nonlinear optical element that consists of a periodically-poled second-order nonlinear optical material and that includes an optical waveguide for parametric amplification of the signal light by using pump light;
• a filter for spectrally separating the amplified signal light from the pump light;
• and
• a synchronization system for synchronizing the phase of the signal light with the phase of the pump light;
• an optical fiber laser amplifier connected just after a phase sensitive amplifier;
• and
• a bandpass filter for passing through a wavelength at around the amplified signal light wavelength;
• and
• a photodiode.

An optical transceiver comprising:

• a phase sensitive amplifier that amplifies signal light based on the optical mixing using a nonlinear optical effect, comprising:
• an optical fiber laser amplifier for amplifying fundamental wave light;
• a second-order nonlinear optical element that consists of a periodically-poled second-order nonlinear optical material and that includes an optical waveguide for generating a sum frequency light from fundamental wave light;
• a filter for separating the sum frequency light from among the fundamental wave light and the sum frequency light;
• a multiplexer for multiplexing the signal light and the sum frequency light that is pump light;
• a second-order nonlinear optical element that consists of a periodically-poled second-order nonlinear optical material, and that includes an optical waveguide for parametric amplification of the signal light by using pump light;
• a filter for spectrally separating the amplified signal light from the pump light;
• and
• a synchronization system for synchronizing the phase of the signal light with the phase of the pump light, and
• a light source for generating the signal light,
• an optical modulator, and
• a circuit for splitting an output from the light source, wherein the part of the split output from the light source is used as the fundamental wave light.