Abstract: An integrated optical signal Synthesizer and Analyzer for optical communications, each formed on a single chip, is disclosed. The Synthesizer and Analyzer are both design to use a Dual-Polarization Quadrature Amplitude Modulation (QAM) for communication operating at high data rates. A communication system for data transmission having such synthesizer and the analyzer is also disclosed.

Abstract: The invention related to the system and method for optical communication using light of two polarization states. Polarization distortion loss (PDL) is compensated by implementation of polarization controllers at both the transmitter and receiver sides. The transmitter controller performs a mixing transformation of beam with two polarizations, while the receiver controller performs the same transformation in the opposite direction with exactly same sequence as in the transmitter part. A cross scrambling and a polarization rotation represented by matrix multiplication are examples of such mixing polarization transformations. The averaged PDL induced errors are corrected by the FEC code plus interleavers.

Abstract: The invention provides a system and method for secure communication that involve encoding and transmitting an optical orthogonal frequency division multiplexed (OFDM) signal. Each subcarrier of an optical carrier in OFDM transmission is modulated with data individually, and a variety of data format are used, such as QPSK, OOK, QAM, etc. The data format of each subcarrier may change in time according to a predetermined pattern. An optical receiver uncovers the data transmitted via an optical link. It is based on a coherent optical receiver and a digital signal processing (DSP) unit. A key to the data mapping and change is transmitted via the same optical link or by a separate channel. In one embodiment, the key is transmitted using quantum encryption technique. Besides subcarrier modulation encoding, the system may provide additional layers of security: optical carrier frequency hopping and polarization scrambling.

Abstract: The present invention relates to an integrated light source having first and second optical waveguides defining a first optical coupling region for coupling light therebetween. At least one of the optical waveguides includes a gain medium configured to emit light upon irradiation. The light source also includes a first acoustic wave source to subject the first optical coupling region to acoustic waves having a longitudinal frequency &ohgr;AC1, whereby a frequency of light propagating along one of the first and second waveguides differs from a frequency of light propagating along the other waveguide by an amount by an amount &ohgr;AC1.