Abstract: A transmitter and transceiver for an optical communication channel may include a data encoder, a partial response (PR) precoder, a pulse filter, and an electrical-to-optical converter to transmit a spread pulse signal over an optical communication channel. The data encoder to encode the transmit data into coded data. The precoder to correlate bits of the coded data together into a precoded signal at the output of the precoder. The pulse filter to spread out the pulses in the precoded signal into a spread-pulse signal at the output of the pulse-shaping filter. The electrical-to-optical converter to convert an electrical spread-pulse signal into light pulses at its optical output. A transceiver may further include an optical-to-electrical converter, an automatic gain controller, a matched filter, a PR finite impulse response equalizing filter, a maximum likelihood sequence estimation detector, and a data decoder in order to decode and recover the data.

Abstract: Methods, apparatus, and systems for an optical communication channel. A data signal is preconditioned prior to transmission over a fiber optic cable to minimize signal distortion and transmitted over a fiber optic cable. Preconditioning may include none, one or more, or all of the following: encoding the data signal using a run length limited code, correlating bits of the data signal, and spreading out the pulses in the time-domain in the data signal. The pulse spreading function can be implemented either in the electrical domain prior to the electrical-to-optical conversion; in the optical domain during and/or after the electrical-to-optical conversion; or a combination of both. During reception, the data signal and clock are recovered. Recovery may include maintaining an amplitude in an electrical signal, filtering the electrical signal, shaping the electrical signal, and removing distortions and intersymbol interference (ISI) from the received electrical signal.

Abstract: Embodiments of fiber optic communication systems are disclosed. In one embodiment, the system includes an optical channel having a channel response, a pulse-shaping transmitter coupled to a first end of the optical channel, and a receiver coupled to a second end of the optical channel. The transmitter includes a spread pulse modulator to shape pulses of data prior to transmission and an electrical to optical converter to transmit electrical data signals as the light signals over the optical channel. The receiver includes an optical to electrical converter to receive light signals from the optical channel and generate electrical data signals and a matched filter to receive and filter the electrical data signals with a response substantially matching a combined response of the transmitter and the channel response to increase a signal to noise ratio thereof.

Abstract: A system and method for transmitting and restoring an optical signal in an optical ring is presented. The optical ring comprises a plurality of nodes, each node containing an optical cross connect switching fabric coupled to a data switch. The optical cross connect switching fabric and the data switch are coupled to a short reach side of a wavelength translation device. A long reach side of the wavelength translation device is coupled to a dense wave division multiplex (DWDM) coupler. The optical cross connect switching fabric and the data switch include a protect channel and a working channel for transporting the optical signal. The wavelength translation device receives the optical signal at a high speed rate, where the optical signal is a short reach optical signal and originates from a high speed interface on the data switch.