Patent ID: 7801451
Filing Date: 2010-09-21
Classification: G02F

Abstract:
1. An intensity modulation/differential phase modulation conversion circuit comprising: an optical phase modulation element; a one-bit delay element; optical directional couplers; and an optical phase modulation circuit comprising: an optical phase modulation element; an optical band pass filter; and an optical directional coupler; wherein control light with a wavelength of λ wherein the control light is given as the control light delayed by a first optical directional coupler and the one-bit delay element; the branching light from the first optical directional coupler is coupled with probe light using a second optical directional coupler; the probe light given as the coupled light output from the second optical directional coupler is phase modulated by control signals via the first optical phase modulation element to give modulated signals; the delayed control light is given as the control light of the optical phase modulation circuit; the phase modulated signals are given as the probe light of the optical phase modulation circuit; and intensity on/off keying modulation of the control light is converted to differential phase shift keying modulation of the probe light.