Abstract: A method and apparatus for transmitting optical pulses in a dispersion-managed optical transmission system comprises determining the pulse width of optical pulses in a optical transmission channel in accordance with the path-average dispersion (PAD) experienced by that channel.

Abstract: A method and apparatus for transmitting optical pulses in a dispersion-managed optical transmission system comprises determining the pulse width of optical pulses in a optical transmission channel in accordance with the path-average dispersion (PAD) experienced by that channel.

Abstract: A method and apparatus for transmitting a modulated optical signal includes a continuous source of light, a first optical modulator for generating an optical pulse stream in response to a radio frequency (RF) driving signal and a DC bias signal, and a second modulator for modulating the optical pulse stream with an electrical data signal. A processor dithers the phase of the RF driving signal using a first dither signal and the level of the DC bias signal using a second dither signal. The processor detects the first and/or second dither signals in the modulated optical signal and adjusts the phase of the RF driving signal and/or level of the DC bias signal to null the detected first and/or second dither signal.

Abstract: Amplified noise signals in an optical communication system can be advantageously used to detect an LOS condition for particular wavelengths of interest. The disclosed method includes generating a sampling window of suitable size and counting the number of transitions in the amplified noise signal that occur during the sampling window. If no transitions occur in a sampling period, then true data is assumed to be present. On the other hand, if transitions occur more frequently than during the period when data are present, an LOS event is deemed to have occurred and an appropriate signal is generated. In another aspect, the disclosed method uses a Clock and Data Recovery (CDR) circuit and adds simple digital logic circuits to detect an LOS condition in a predetermined sampling window.

Abstract: A method and apparatus for transmitting a modulated optical signal includes a continuous source of light, a first optical modulator for generating an optical pulse stream in response to a radio frequency (RF) driving signal and a DC bias signal, and a second modulator for modulating the optical pulse stream with an electrical data signal. A processor dithers the phase of the RF driving signal using a first dither signal and the level of the DC bias signal using a second dither signal. The processor detects the first and/or second dither signals in the modulated optical signal and adjusts the phase of the RF driving signal and/or level of the DC bias signal to null the detected first and/or second dither signal.

Abstract: A common Modular Carrier (MC) unit shares power and control among a plurality of Optical Network Units (ONU) which are plugged into it, thereby increasing the ONU density in an existing equipment shelf. In one embodiment, the MC unit together with its four ONU units is arranged to slide into an existing card slot of the existing equipment shelf and occupy the space of the adjacent slot. The result is a doubling of the capacity over the conventional technique of using a separate slot for each ONU unit.

Abstract: The invention is directed to an optical node, e.g., a so-called add/drop site, that receives an optical carrier signal formed from a plurality of component optical signals of respective wavelengths and a plurality of different identification signals which identify respective ones of the wavelengths. As is typically the case, the node includes a demultiplexer that demultiplexes the optical carrier signal and outputs the demultiplexed component optical signals to respective optical paths. Disadvantageously, each of the demultiplexed optical component signals includes all of the identification signals as a result of such demultiplexing. However, we dispose an optical translator unit in at least one of the optical paths to remove all of the identification signals from the one component optical signals and also reset the power level of that signal.

Abstract: A multiplexer is arranged for interleaving blocks of bits from tributary lines. Sequences of blocks of digital bit streams are received in frames from each tributary line. Each frame includes tributary line identification information and plural blocks of bits. Each block of digital bits includes plural data bits and a parity bit. The sequence of blocks from one tributary line also includes in a periodic one of the parity bit positions, a bit containing control information. The blocks of digital bit streams are multiplexed into a single multiplexed bit stream.