Patent ID: 9722707
Date: 2017-08-01
CPC Classifications: H04B

Claim:
1. A direct detection method using a dual-channel orthogonal carriers assisted optical signal comprising: generating a first optical carrier and a second optical carrier having different carrier frequencies; coupling the first optical carrier with the second optical carrier to generate a first combined signal path; modulating the first optical carrier and the second optical carrier in the first combined signal path simultaneously with a modulation signal to generate a first modulated signal and a second modulated signal; shifting a phase of the second optical carrier by 90 degrees to generate a phase-shifted second optical carrier, and coupling the first optical carrier with the phase-shifted second optical carrier to generate a second combined signal path; and with the first optical carrier in the second combined signal path as a first optical pilot, and with the phase-shifted second optical carrier in the second combined signal path as a second optical pilot, coupling the first optical pilot with the first modulated signal and coupling the second optical pilot with the second modulated signal to generate and transmit the dual-channel orthogonal carriers assisted optical signal to be detected.