Patent ID: 6211996
Filing Date: 2001-04-03
Classification: H03C,H04B

Abstract:
An angle modulator for converting an input modulating signal into an angle-modulated signal through homodyne detection, comprising:a light source emitting a light;an optical branching part branching the light emitted by said light source into a first light and a second light;an optical intensity modulator performing optical intensity modulation or optical amplitude modulation on said first light with a first electrical signal having a predetermined frequency fc, and outputting an optical-intensity-modulated or optical-amplitude-modulated signal as a first optical signal;a first optical angle modulator performing optical angle modulation on said second light with a second electrical signal, which is said input modulating signal, and outputting an optical-angle-modulated signal as a second optical signal;an optical coupler coupling said first and second optical signals; anda photo-detector with a square-law detection characteristic converting an optical signal outputted from said optical coupler into an electrical signal and outputting the electrical signal as said angle-modulated signal having a carrier frequency fc.