Abstract:
An optical device including dynamic channel equalization is provided. In an exemplary multiplexer or line amplifier configuration the device includes a plurality of separate optical paths, each of which receiving a separate group of optical signals. Each group of optical signals is provided to an associated variable optical attenuator. Separate inputs of an optical combiner are each coupled to an output of an associated one of the variable optical attenuators. The optical combiner has an output providing the separate groups of optical signals in an aggregated form on an aggregate optical signal path. An optical performance monitor is coupled to the aggregate optical signal path, and is configured to detect an optical signal power of each of the separate groups. The monitor supplies a feedback signal to corresponding ones of the variable optical attenuators for adjusting a respective attenuation associated with each of the attenuators in dependence of the detected optical signal powers. The device may also be provided in a demultiplexer configuration.
Abstract:
An optical device including dynamic channel equalization is provided. In an exemplary multiplexer or line amplifier configuration the device includes a plurality of separate optical paths, each of which receiving a separate group of optical signals. Each group of optical signals is provided to an associated variable optical attenuator. Separate inputs of an optical combiner are each coupled to an output of an associated one of the variable optical attenuators. The optical combiner has an output providing the separate groups of optical signals in an aggregated form on an aggregate optical signal path. An optical performance monitor is coupled to the aggregate optical signal path, and is configured to detect an optical signal to noise ratio of each of the separate groups. The monitor supplied a feedback signal to corresponding ones of the variable optical attenuators for adjusting a respective attenuation associated with each of the attenuators in dependence of the detected optical signal to noise ratios. The device may also be provided in a demultiplexer configuration.
Abstract:
An optical device is provided which locks the wavelength output of a laser transmitter in an optical transmission system as well as preventing the propagation of unwanted signals generated by the laser transmitter prior to the transmitter reaching the desired operating wavelength thereby reducing crosstalk between channels within a wavelength division multiplexed communication system.
Abstract:
In accordance with the present invention, an in-line fiber Bragg grating is coupled to the output of a directly modulated DFB laser. The grating preferably rejects chirp induced frequencies of light emitted by the DFB laser. Accordingly, light transmitted through the grating is spectrally narrowed and has a higher extinction ratio, thereby decreasing bit error rate probabilities.
Abstract:
In accordance with the present invention, an optical device is provided which selects narrowly spaced optical channels used in dense wavelength division multiplexed systems. The device includes a first and second Bragg gratings in a cascaded configuration where each grating has a length which is shorter than a single grating configured to select a channel within a narrowly spaced channel plan. When taken together, the two Bragg gratings provide a narrow bandwidth wavelength selection device for narrowly spaced optical channels while avoiding manufacturing drawbacks associated with writing long gratings.
Abstract:
A wavelength filter has a low index waveguide, a high index waveguide and a grating for coupling therebetween. The high index waveguide is in horizontal proximity to said low index waveguide. The low index waveguide and said high index waveguide have substantially different geometries which result in substantially different indices. A method for fabricating the wavelength filter is also disclosed.
Abstract:
An apparatus and method is provided for optical cross connections. A guide structure is used to guide optical fiber fed to various stations on the guide structure which correspond to input and output ports of a fiber shuffle interconnect. Once the fiber has been positioned about the guide structure, the fiber is arranged such that the input and output ports of the interconnect align allowing the fibers to be bundled to a common input and/or output port. In this manner, once the fiber is arranged about the guide structure, fiber management becomes an easy task because the number of fiber bundles is significantly smaller than the total number of individual fibers.