Alphion Corporation

Jithamithra Sarathy

Boris Stefanov

Bharat P Dave

Tan Buu Thai

Ronald Simprini

Kwang S Kim

Doruk Engin

Julio Martinez

Olga Nedzhvetskaya

Mohammad Laham

Ganesh Lakshminarayana

David Lidsky

Roman Antosik

Gaurav Naik

Jayanta Das

Hongsheng Wang

Ruomei Mu

Michael Evans

Chinnabbu Ekambaram

Scott Kaminski

Kuo-Ming Lee

Roanld Simprini

Olga Nedzhvetska

Aleksandr Miglo

Tan Thai

David B Lidsky

Monitoring of the input power is performed on-chip and is used to monitor and maintain performance, detect failure and trigger network protection strategies. An optical power-monitoring technique uses a photodetector monolithically integrated with the semiconductor optical amplifier&#x2014;Mach-Zehnder interferometer circuit to monitor the P2R device and keep the output stable while the input power varies.

Integrated performance monitoring, performance maintenance, and failure detection for photonic regenerators

A integrated optical circuit comprises an interferometer having a first optical path and a second optical path configured for regenerating an input signal entering the first path by interference at a first coupler between continuous wave (CW) signals from the two optical paths, and a third optical path configured such that a canceling signal passing therethrough cancels, at a second coupler, a traveling signal from the first arm. When the device is operated in a counter-propagative mode, the traveling signal is the CW signal from the first arm. When the device is operated in a co-propagative mode, the traveling signal is the input signal from the first arm.

Photonic integrated circuit

A system, method and device for AO2R is presented. The AO2R system presented is redundant, containing multiple pathways for the input and output signals to travel. The system carries out both the regeneration and reshaping functions in the optical domain, and returns a clean output signal at the same bit rate and in the same format as the input signal, on a wavelength of choice. As an all optical device, the apparatus is bit rate and format transparent, and requires no optical-electrical-optical conversion. The system's built in redundancy and symmetry allows less than perfect yields on components to be tolerated, thus increasing the utility of devices manufactured with less than perfect yields. In alternative embodiments the redundancy aspect of the invention can be extended to any optical signal processing device, thus facilitating high availability optical signal processing.

Redundant path all-optical regeneration, reshaping and wavelength conversion for enhanced yield

Method and apparatus are presented for the generation and detection of maintenance signals in an optical data network. The maintenance signals are such that they can be read both by high bit-rate and low bit-rate receivers. Detection of the maintenance signals occurs in two stages. In a low bit-rate first stage each nodal input port is sampled in a round robin fashion to detect the presence of a maintenance signal. In a high bit-rate second stage the maintenance signal is verified and read by a high speed receiver, along with other high bit-rate information transmitted with it. One second stage high speed receiver is shared among M input channels for cost and circuit efficiency.

Generation and detection of optical maintenance signals in optical networks

A method and apparatus for a tunable optical spectrum analyzer that can measure the optical spectrum of a demultiplexed DWDM signal are presented. The signal level and Optical Signal to Noise Ratio (OSNR) of an individual channel of the DWDM signal can be obtained from the measured optical spectrum. The device employs a rapid tuning and detection technique to obtain the optical spectrum of the incoming signal. In a preferred embodiment the apparatus is fabricated on a single chip resulting in a compact measurement device. Using the device of the preferred embodiment, single channel OSNR can be determined in as small a time interval as approximately 225 microseconds. Using an array of these devices an entire DWDM mixed signal can be monitored as to OP and OSNR in the same time interval.

Method and apparatus for bit-rate and format insensitive performance monitoring of lightwave signals

A single device for amplifying and multiplying an optical signal is presented. The device is an InP-semiconductor-based amplified multimode interferometer. The three main sections of the device are an input port, an interference and amplification region and N output ports. The input port is a single channel waveguide. The interference and amplification section supports a large number of modes which interfere with one another. By carefully choosing the length of the interference/amplification region to correspond to the constructive interference condition for N equally spaced channel modes, we can reproduce N amplified signals. In an alternate embodiment, by shaping the gain region into a cross pattern, corner reflections and consequent side channel signal distortion in the output can be minimized.

Device and method for simultaneous multiple reproduction of lightwave signals

A method and circuit are presented for the all optical recovery of the clock signal from an arbitrary optical data signal. The method involves two stages. A first stage preprocesses the optical signal by converting a NRZ signal to a PRZ signal, or if the input optical signal is RZ, by merely amplifying it. In a preferred embodiment this stage is implemented via an integrated SOA in each arm of an asymmetric interferometric device. The output of the preprocessing stage is fed to a clock recovery stage, which consists of a symmetric interferometer that locks on to the inherent clock signal by using the second stage input signal to trigger two optical sources to self oscillate at the clock rate. In a preferred embodiment the second stage is implemented via SOAs integrated in the arms of an interferometer, with two DFB lasers as terminuses. The output of the interferometer is an optical clock signal at the clock rate of the original input.

Bit-rate and format insensitive all-option clock extraction circuit

Bit-rate and format insensitive all-optical clock extraction circuit

A method and system for AO R functionality is presented. The system includes an AO R device followed by an AOCR clock recovery module and an AOR retiming device. The AOR retiming device takes as input a recovered clock signal extracted from the output of the AO R by the AOCR clock recovery module. The output is the recovered clock signal gated by the regenerated and reshaped input signal, and a monitor circuit is used to set the optimum operations of the retiming device. In a first embodiment the output of the AOR retiming device is fed to an AOC code and wavelength conversion output stage, which returns the signal to the NRZ coding, on a service wavelength converted to match the fixed wavelength connection with the DWDM transmission system. In a second embodiment the code conversion is incorporated into the AOR retiming device, and wavelength conversion is accomplished in the AOCR clock recovery device.

Bit-rate and format insensitive all-optical circuit for reshaping, regeneration and retiming of optical pulse streams

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Atlantic Highlands, NJ, United States of America

Jithamithra Sarathy