Abstract: The present method is for generating a 4-level optical signal and it includes providing a continuous wave CW optical source; modulating the CW optical source with a first intensity modulator driven by a binary electrical signal a n Gbits/s to generate an optical signal; employing a second intensity modulator as a pulse carving modulator that is driven by an RF signal at n GHz thereby generating a 4 level optical signal for subsequent detection by a receiver.

Abstract: Optical superchannel methods and systems that couple two or more local oscillators into a single coherent receiver front end to receive multiple optical subcarriers are shown and described. With multiple local oscillators coupled into a single coherent receiver and appropriate optical selective filtering of the superchannel signal, non-neighboring subcarriers may be received by the single coherent optical receiver.

Abstract: An optical communication system includes a polarization multiplexed orthogonal frequency-division multiplexing POLMUX-OFDM transmitter for generating a POLMUX-OFDM double sideband signal, an optical processing path for processing the double sideband signal from the transmitter; an analog-to-digital convert ADC-OFDM receiver coupled to the optical processing path for receiving the double sideband signal processed by the optical path; and a block-diagonal multiple-input multiple-output MIMO equalizer responsive to the receiver for enabling correct operation for a completely random incoming signal polarization state without adaptive polarization control at said receiver, which enables complexity.

Abstract: A system to communicate optical data signals in parallel includes an optical splitter to split the data signals into two polarization multiplexed (PM) signals; and two reception channels coupled to the optical splitter, where each reception channel tracks and isolates a PM signal independently.

Abstract: Systems and methods are disclosed for a filter-less coherent receiving system with a filter-less coherent receiver frontend; a signal-signal beat-noise detector coupled to the filter-less coherent receiver frontend; and a real-time processor coupled to the filter-less coherent receiver frontend and the signal-signal beat-noise detector to reject signal-signal interference.

Abstract: An analog to digital converter (ADC) structure and method includes a photonic filter bank having at least two filters. The at least two filters are configured to create a corresponding spectral tributary from an input signal at a target rate, and the at least two filters are configured to exhibit orthogonality properties between respective tributaries. An optical/electrical (O/E) converter is coupled to each of the at least two filters in a respective spectral tributary to convert an optical input to an electrical output. An analog to digital converter (ADC) is coupled to each of the O/E converters in a respective spectral tributary to sample the electrical output at a fraction of a target rate and to convert a sampled analog electrical output into a digital signal. A synthesis filter is coupled to each of the ADCs in a respective spectral tributary to reconstruct the input signal digitally at the target rate.

Abstract: A method of processing data is provided that includes receiving a plurality of binary electronic signals and generating an optical signal by a number of lasers that is equal to or greater than the number of binary electronic signals. The optical signal is generated at one of a plurality of intensity levels, and each intensity level represents a particular combination of bit values for the plurality of binary electronic signals. The optical signal is converted into an electronic signal having the plurality of intensity levels. An apparatus for processing data is provided that includes a plurality of lasers configured to emit light at a plurality of frequencies, and a plurality of modulators configured to receive a plurality of binary electronic signals and to modulate the light emitted by the lasers. An apparatus for transmitting data is provided that includes a photo receiver and an electronic signal generator.

Abstract: A method includes modulating lightwaves to provide first and second OFDM signal sidebands at a first polarization direction and first and second OFDM signal sidebands at a second polarization direction, and combining sidebands that are oppositely positioned and joined from the first and second OFDM signal sidebands at each polarization direction to provide a polarization multiplexing OFDM signal.

Abstract: A polarization multiplexing, orthogonal frequency division multiplexing (POMUX) transmission system utilizing direct detection.

Abstract: A system to communicate optical data signals in parallel includes an optical splitter to split the data signals into two polarization multiplexed (PM) signals; and two reception channels coupled to the optical splitter, where each reception channel tracks and isolates a PM signal independently.

Abstract: A method and apparatus for all optical orthogonal frequency division multiplexing (OFDM) employing Inverse Fast Fourier Transform/Fast Fourier Transform by integrated coupler interferometrically.

Abstract: An analog to digital converter (ADC) structure and method includes a photonic filter bank having at least two filters. The at least two filters are configured to create a corresponding spectral tributary from an input signal at a target rate, and the at least two filters are configured to exhibit orthogonality properties between respective tributaries. An optical/electrical (O/E) converter is coupled to each of the at least two filters in a respective spectral tributary to convert an optical input to an electrical output. An analog to digital converter (ADC) is coupled to each of the O/E converters in a respective spectral tributary to sample the electrical output at a fraction of a target rate and to convert a sampled analog electrical output into a digital signal. A synthesis filter is coupled to each of the ADCs in a respective spectral tributary to reconstruct the input signal digitally at the target rate.

Abstract: In an optical transmission system, data is transmitted via an optical beam modulated with an arbitrary waveform. The optical beam is transmitted through at least one optical element. Transmission through at least one optical element degrades the signal quality of the initial optical beam. The signal characteristics of at least one optical beam at the output of least one optical element are used as feedback to shape the arbitrary waveform to improve signal characteristics. An arbitrary waveform may be used to compensate signal degradation caused by a multiplexer/demultiplexer in a wavelength division multiplex system.

Abstract: A system and method for virtual I/Q multiplexing in optical code division for secure local area OFDM includes encoding a wide spectrum signal, which includes a plurality of spectral bins, to provide a complementary spectral coding over at least two channels. The complementary spectral codings are intensity modulated with opposite polarity for each channel. An M-ary Orthogonal Frequency Division Multiplexing (OFDM) signal is modulated using the complementary spectral codings of opposite polarity with separate complementary spectral encoded (CSE) optical codes to provide a virtual in-phase (I) and quadrature (Q) (I/Q) multiplexing for the OFDM signal.