Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In accordance with the present invention, an optical device is provided that includes an N×N network, where N is an integer greater than or equal to 2. The network has N input ports for receiving optical input energy and N output ports for providing optical output energy. The optical output energy at each of the output ports arises from interference among the optical input energy received at the input ports. (N−1) feedback paths optically couple (N−1) of the input ports of the N×N network to (N−1) of the output ports of the N×N network. A first optical waveguide, which is provided for receiving an input optical signal, is coupled to a remaining one of the input ports of the N×N network. A second optical waveguide, which is provided for the exit of an output optical signal, is coupled to a remaining one of the output ports of the N×N network.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.