Optical communication system for passive optical networks and high data rate communication

Abstract

A bi-directional optical communication system employing a minimum number of single-mode high repetition rate pulsed optical signal sources to achieve cost efficiency while maintaining high data rates. The bi-directional optical communication system includes a first optical data processing unit and a second optical data processing unit. The first optical data processing unit modulates a pulsed optical source using a differential quadrature phase shift keying (DQPSK) modulation and two-level pulse amplitude (PAM-2) modulation and then demodulates it to achieve a pulse amplitude modulated signal. The second optical data processing unit reuses the same optical carrier by passing it through a regenerative wavelength converter to generate three pulsed optical carriers at different wavelengths and employs an On-off keying (OOK) modulation scheme. These carriers are employed to send uplink data at a same rate of as the downlink. As a result, large data is transmitted from one data center to another data center through a downlink and uplink free space optical link network.