US 2002/0171900 A1 · Method and circuit for generating single-sideband optical signal

Abstract

The present invention relates to a method for generating a single-sideband optical signal. According to the method, as data signals having a 90-degree phase difference with respect to input data signals, which are NRZ signals at 10 Gb/s, 0.5-bit delay data signals are generated by a 0.5-bit delay circuit for obtaining a delay corresponding to π/2 of the bit period of the input data signal. An SSB optical signal produced from the data signals and the 0.5-bit delay data signals is generated through an optical filter. Further, to eliminate a residual intensity-modulated component, the generated SSB optical signal is fed back to appropriately adjust the center frequency of the optical filter. The carrier output frequency of a semiconductor laser can be adjusted instead of the center frequency of the optical filter. When an RZ signal is used as an input data signal, a 0.25-bit delay circuit is used.

Claims14

Dependent claims

A method for generating a single-sideband optical signal, comprising the steps of:

performing chirpless 0-π optical phase modulation on carrier wave light in accordance with a required data signal in order to generate a single-sideband optical signal;
passing the generated single-sideband optical signal through an optical filter;
directly detecting the single-sideband optical signal using a photoreceiver;
detecting the magnitude of a residual intensity-modulated component from an output signal of the photoreceiver;
and
controlling the center frequency of the optical filter so that the magnitude of the residual intensity-modulated component is always minimized.

3 more elements

A method for generating a single-sideband optical signal, comprising the steps of:

splitting carrier wave light into first carrier wave light and second carrier wave light;
performing chirpless 0-π optical phase modulation on the first carrier wave light in accordance with a required data signal using a first optical phase modulator in order to generate first phase-modulated light;
generating a bit-delay data signal having a delay corresponding to π/2 of a bit period of the required data signal inputted;
performing chirpless 0-π optical phase modulation on the second carrier wave light in accordance with the bit-delay data signal using a second optical phase modulator in order to generate second phase modulated light;
and
combining the first phase-modulated light with the second phase-modulated light so that a phase difference between individual carrier waves thereof is set to 90 degrees in order to generate a single-sideband optical signal.

3 more elements

Dependencies are inferred from the claim text.

Method and circuit for generating single-sideband optical signal

Life of this patent

Method and circuit for generating single-sideband optical signal

Life of this patent

Abstract

Claims14