Lucent Technologies Inc.

Inplane Photonics, Inc.

Tek-Ming Shen

Sergey V Frolov

Joseph Shmulovich

Wenhua Lin

Allan James Bruce

Paul Francis Wysocki

Nathan Myron Denkin

An optical module is provided for performing a prescribed function such as dispersion compensation, for example. The optical module is to be integrated between stages of a multi-stage rare-earth doped optical amplifier. The module includes an input port for receiving optical energy from one stage of the rare-earth doped optical amplifier and a rare-earth doped planar waveguide coupled to the input port. An optically lossy, passive element is provided for performing the prescribed function. The optically lossy, passive element is coupled to the planar waveguide for receiving optical energy therefrom. An output port is coupled to the optically lossy, passive element for providing optical energy to another stage of the rare-earth doped optical amplifier. The rare-earth doped planar waveguide has a first unsaturated absorption spectrum and the rare-earth doped optical amplifier has a second unsaturated absorption spectrum such that the ratio of the first to the second absorption spectrum is substantially wavelength independent within the spectral range of incoming and outgoing optical energy. The rare-earth doped planar waveguide has a length determined at least in part from a value of optical loss in the passive element and characteristics of the rare-earth doped optical amplifier.

Optical module including an optically lossy component and an erbium-doped waveguide for insertion between stages of an optical amplifier

A multistage optical amplifier includes a fiber amplifier stage having an active optical fiber for imparting gain to an optical signal propagating therethrough and a coupler supplying pump energy to the optical fiber. A planar waveguide amplifier stage is optically coupled to the fiber amplifier stage. The waveguide amplifier including a substrate, an active planar waveguide formed on the substrate for imparting gain to an optical signal propagating therethrough, and at least one waveguide coupler formed on the substrate for coupling pump power to the active planar waveguide.

Multistage optical amplifier having a fiber-based amplifier stage and a planar waveguide-based amplifier stage

Substantial reduction in crosstalk and improved scalability for supporting high channel counts in dense wavelength division multiplexed (DWDM) systems is achieved in an optical demultiplexer arrangement that partitions the total number of input optical channels into separate demultiplexer modules, demultiplexes smaller groups of optical channels in the separate demultiplexer modules, and filters the individual optical channels at the outputs of the separate demultiplexer modules. Partitioning the total number of channels into smaller demultiplexing groups and post-filtering a reduced number of demultipexed optical channels reduces the number of non-adjacent channels that can contribute to the total crosstalk level. The modularity of the optical demultiplexer arrangement results in smaller device footprints and smaller free spectral ranges associated with the demultiplexer modules. This modularity also allows for future system upgrades without redesign and without disruption to existing service. In one illustrative embodiment, the optical demultiplexer arrangement includes a splitter or filter for directing the multi-wavelength input optical signal to one or more demultiplexer modules. Each of the demultiplexer modules separates a received multi-wavelength optical signal into individual wavelength channels. The individual wavelength channels are then supplied to bandpass post-filters which are coupled to each of the outputs of the demultiplexer modules.

Scalable optical demultiplexing arrangement for wide band dense wavelength division multiplexed systems

A scheme is described for controlling adjacent channel crosstalk so that an optical receiver can accurately detect the presence of a signal in its respective optical channel after a loss of signal condition occurs. According to illustrative embodiments of the invention, crosstalk-induced cross-traffic is prevented so that traffic from an adjacent channel is not carried in a channel that is out of service due to a loss of signal condition. More specifically, adjacent channel crosstalk, which might otherwise exceed the receiver sensitivity threshold of the failed channel, is substantially reduced or eliminated so that a receiver will not improperly identify and lock onto an adjacent channel thereby causing the cross-traffic condition.

Cross-traffic suppression in wavelength division multiplexed systems

An integrated wavelength router for use in a wavelength division multiplexing system is disclosed. Input waveguides deliver a plurality of optical signals to a first slab coupler which is in turn coupled to an optical grating waveguide. A second slab coupler is coupled to the output of the optical grating waveguide which is in turn coupled to output waveguides. The input and output waveguides transmit data channels of the wavelength division multiplexing system and include out-of-band signals such as a supervisory signal or a pilot signal with different channel bandwidths. WDM systems utilizing the router of the present invention can reduce power losses and therefore increase the span length of the wavelength division multiplexing system.

Optical multiplexer/demultiplexer arrangement for WDM signals having in-band and out-of-band signal components

An apparatus is provided to compensate for dispersion in a transmission medium. The apparatus includes an input port for receiving a WDM optical signal having a plurality of signal wavelengths and a first Bragg transmission grating receiving the WDM optical signal from the input port. The first Bragg transmission grating has non-zero dispersion at at least one of the signal wavelengths. The first Bragg transmission grating also has a Bragg wavelength that is chosen so that all of the plurality of signal wavelengths lie outside of a reflection band of the first Bragg transmission grating. A second Bragg transmission grating, which is optically coupled to the first Bragg transmission grating, has a non-zero dispersion at at least one of the signal wavelengths. The second Bragg transmission grating also has a Bragg wavelength that is selected so that all of the plurality of signal wavelengths lie outside of a reflection band of the second Bragg transmission grating. Finally, an output port is provided for receiving the optical signal from the second Bragg grating and communicating the optical signal to an external source.

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Westfield, NJ, United States of America

Tek-Ming Shen