Agilent Technologies, Inc.

Cselt-centro Studi E Laboratori Telecomunicazioni S.p.a.

Roberto Lano

Eduardo Augusto Miranda Sologuren

Riccardo Calvani

Piero Gambini

Cristiana Contardi

Emilio Vezzoni

Libero Zucchelli

Franco Delpiano

Giuseppe Ferraris

Roberto Cadeddu

Giampaolo Bendelli

An optical communication module includes an optical radiation source as well as control circuitry to control the temperature and the power emitted by he optical source. In order to permit soft start-up of the source while avoiding undesired wavelength variations, the optical source is pre-heated before being caused to emit optical radiation. This may be effected by initially heating the optical source to an initial temperature using the thermoelectrical conditioner associated therewith as a heater and subsequently causing a partly under-threshold current to flow through the source, thus causing the source to be heated while still emitting negligible optical power.

Method and system for turning on an optical radiation source

An optical communication module includes an optical radiation source as well as control circuitry to control the temperature and the power emitted by the optical source. In order to permit soft start-up of the source while avoiding undesired wavelength variations, the optical source is pre-heated before being caused to emit optical radiation. This may be effected by initially heating the optical source to an initial temperature using the thermoelectrical conditioner associated therewith as a heater and subsequently causing a partly under-threshold current to flow through the source, thus causing the source to be heated while still emitting negligible optical power.

A receiver for optical signals arranged in packets of data having a discontinuous flow pre-reads the signal and generates, for each packet, a corresponding signal indicating the phase of the data in the packet, and a threshold level indicating the packet mean signal power. A delay line delays the discontinuous flow by a delay interval. A receiver responsive to the discontinuous flow delayed by the delay line performs, on each packet, a receiving operation on the basis of the threshold level and with a phase identified on the basis of the phase indicating signal.

Receiver for signals in a discontinuous flow and corresponding receiving process

A device for monitoring the emission wavelength of a laser includes a semiconductor slice or slab having first and second opposed surfaces. The semiconductor slice is exposed to the radiation at an angle such that a portion of said radiation impinges onto the first surface at angles in the vicinity of the Brewster angle for the first surface. The radiation is thus refracted into the semiconductor slice and caused to propagate towards the second surface of the semiconductor slice. A wavelength selective filter is arranged at said second surface having associated a photodetector to generate a signal indicative of the wavelength of the radiation.

Device for monitoring the emission wavelength of a laser

The optical add/drop multiplexer has a pair of nominally identical interference filters, one of which carries out the function of extracting a carrier from a wavelength division multiplexed stream and the other the insertion function. The filters are arranged in parallel planes and are secured to opposite faces of a transparent plate so that the stream exits the device after having undergone reflection by both filters. The plate is mounted on a support which can be rotated in either direction to vary the tuning wavelength of the filters.

Optical add-drop multiplexer for optical communication networks

In a ring network communication structure for communication on an optical carrier (3A, 3B), a plurality of nodes (2A, . . . , 2E) are interconnected by means of connections comprising at least a first (3A) and a second (3B) optical carrier, such as an optical fiber. Transmission occurs on the ring according to a WDM scheme, by utilizing a first wavelength (.lambda..sub.1) for communication in one direction on the first carrier (3A) of said pair, while communication in the opposite direction occurs by employing a second wavelength (.lambda..sub.2) on the other optical carrier (3B). In the presence of a failure on one of the connections, the nodes adjacent (2B, 2C) to the failed connection reconfigure themselves to ensure the continuation of communication on the alternative path provided by the ring, by utilizing the first wavelength (.lambda..sub.1) on the second carrier (3B) and the second wavelength (.lambda..sub.2)on the first carrier (3A). Preferential application to SDH optical fiber ring networks.

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Almese, Italy

Roberto Lano