Patent application number | Description | Published |
20100296819 | Optical Receivers and Communication Systems - Optical communications systems and methods transmit signals through an optical medium at a rate associated with a symbol interval. Receivers are communicatively coupled to the optical medium, and receive the signals. The received signals are processed using a plurality of filters. Each filter is used sequentially, one per symbol interval, during a sequence of consecutive symbol intervals. In certain exemplary embodiments, the tap spacing is K/M times the symbol interval, where K is the number of filters used, and M is an integer greater than K. | 11-25-2010 |
20110249969 | POWER OPTIMIZATION OF OPTICAL RECEIVERS - An optical receiver system is disclosed. The system includes a local oscillator, a mixer and a processor. The local oscillator is configured to generate a laser signal to indicate a selection of one of a plurality of channels. In addition, the mixer is configured to receive signals on the plurality of channels and to utilize the laser signal to distinguish the signal on the selected channel. Further, the processor is configured to maximize a power level difference between the laser signal and at least one of the plurality of channels based on a total number of the plurality of channels by adjusting the power of the laser signal input to the mixer to limit a noise penalty in the receiver system. | 10-13-2011 |
20120262780 | MULTIMODE OPTICAL AMPLIFIER WITH CLOSE-LOOP MODAL GAIN CONTROL - Systems and methods for amplification are shown that include a pump preparation module configured to provide a pump output that includes a plurality of pump modes; an amplification module configured to accept a multimode signal input and the pump output, such that the pump output causes an amplification of a plurality of modes in the signal input to produce an amplified signal output; and a gain control module configured to adjust a balance of the plurality of pump modes in the pump output to produce a predetermined amplified signal output. | 10-18-2012 |
20120263481 | NONLINEAR COMPENSATION USING AN ENHANCED BACKPROPAGATION METHOD WITH SUBBANDING - Systems and methods are disclosed to perform nonlinear compensation (NLC) in an optical communication system by applying digital backpropagation (DBP) using a frequency-shaped split-step Fourier method (FS-SSFM), and processing a data block using an overlap-and-save method with a block size M and an overlap factor of N samples between adjacent blocks. | 10-18-2012 |
20120294614 | Symmetric Coherent OFDMA-PON Configuration with Low-Speed ONU-Side - A method by an optical network unit ONU includes, for downstream transmission, using a first tunable laser for coherent detection on a sub-band basis to increase receiver sensitivity and reduce analog-to-digital conversion ADC and digital signal processor DSP requirements within the ONU, and for upstream transmission, using a second tunable laser and using an optical signal beating between the first and second tunable lasers to generate a tunable radio frequency RF signal source for upstream multi-band OFDMA signal generation thereby avoiding need for an otherwise more costly RF clock source within the ONU, enabling low-speed digital-to-analog conversion DAC operation and rendering the ONU colorless in both optical and radio frequency RF domains. | 11-22-2012 |
20120301142 | Optical Superchannel Method and System - Optical superchannel methods and systems that couple two or more local oscillators into a single coherent receiver front end to receive multiple optical subcarriers are shown and described. With multiple local oscillators coupled into a single coherent receiver and appropriate optical selective filtering of the superchannel signal, non-neighboring subcarriers may be received by the single coherent optical receiver. | 11-29-2012 |
20120321323 | Variable Line-Rate Optical Transmitter by Modulation Format Hopping Using Electrical-Optical-Electrical EOE Generated QAM Signal - The present method is for generating a 4-level optical signal and it includes providing a continuous wave CW optical source; modulating the CW optical source with a first intensity modulator driven by a binary electrical signal a n Gbits/s to generate an optical signal; employing a second intensity modulator as a pulse carving modulator that is driven by an RF signal at n GHz thereby generating a 4 level optical signal for subsequent detection by a receiver. | 12-20-2012 |
20140063592 | 6x28-Gbaud Few-Mode Fiber Recirculating Loop Transmission with Gain-Equalized Inline Few-Mode Fiber Amplifier - Disclosed herein are methods, structures and systems for few-mode fiber (FMF) transmission including an optical amplifier exhibiting modal gain control suitable for such transmission in which higher order modes are amplified. An exemplary evaluation system is described and results presented. | 03-06-2014 |
20140313469 | RECONFIGURABLE 1xN FEW-MODE FIBER OPTICAL SWITCH BASED ON A SPATIAL LIGHT MODULATOR - An optical switch includes an array of parallel few-mode fibers stacked vertically; beam stretchers that modifies an aspect ratio between a height and a width of beams associated with each few-mode fiber; a spatial light modulator with a 2D array of independently programmed tunable pixels, wherein the spatial light modulator manipulates phase and/or amplitude at each position of an incident optical beam; a wavelength demultiplexer which can separate the spectral components of an incident beam in angle; and lenses for imaging the modes of the input array of fiber to the spatial light modulator. | 10-23-2014 |