Lucent Technologies Inc.

At&t Bell Laboratories

Other

Alcatel-lucent USA Inc.

Alcatel Lucent

Agere Systems Guardian Corp.

Agere Systems Optoelectronics Guardian Corp.

Lgs Innovations LLC

Jane Deborah LeGrange

John J Burack

Inuk Kang

Kenneth L Walker

Pietro Arturo Bernasconi

Susanne C Arney

Treliant Fang

Jose A Ors

Linda M Braun

David John DiGiovanni

Christi Kay Madsen

Kok Wai Chang

William Alfred Reed

Wesley P Townsend

Sandra Greenberg Kosinski

William Robert Holland

Alex Pidwerbetsky

Timothy M Miller

Mihaela Dinu

Eva Milar Vogel

Richard V Kollarits

Gerald Edward Tourgee

Douglas P Holcomb

Alexandru Paunescu

Albin Lloyd Kasper

A free-space optical communication method is provided. The method includes generating, at a transmitter of a satellite, an optical frequency comb and a pump signal, modulating the optical frequency comb to generate a data signal and an idler signal that is a phase conjugate of the data signal, attenuating the pump signal, transmitting over free-space, from the satellite, a communication signal having the data signal, the idler signal and the pump signal, receiving from the satellite, at a receiver, the transmitted communication signal having the data signal, the idler signal, and the attenuated pump signal, amplifying, at a phase-sensitive amplifier, the data signal and the idler signal, and demodulating the data signal and the idler signal to extract data.

Free space optical communication system and method

A free-space optical communication method is provided. An example method may include generating an optical frequency comb comprising a first tone and a second tone different from the first tone. The method may include modulating, by a first modulator of a first device, the first tone to generate a first signal comprising data. The method may include modulating, by a second modulator of the first device, the second tone to generate a second signal that is a phase conjugate of the first signal. The method may include transmitting, via free-space and to a second device, a communication signal having the first signal and the second signal.

A slot waveguide for electro-optic modulation is provided. The slot waveguide includes a slot and Bragg gratings defined by outer walls of the slot. The Bragg gratings are configured to slow an optical signal. The slot defines a low-refractive index region and the Bragg gratings spaced apart by the slot define a high-refractive index region. The slot waveguide includes a pair of electrodes extending parallel and adjacent to the slot waveguide. The electrodes are configured to carry an electrical modulation signal to induce a change in a phase of the optical signal. The slot of the slot waveguide is at least partially filled with an electro-optic polymeric material poled in a direction orthogonal to a direction of propagation of the optical signal in the slot waveguide.

Integrated low-voltage CMOS-compatible electro-optic modulator

According to one embodiment, a multiplex delay unit comprises an optical all-pass filter (OAPF) adapted to apply continuously tunable group delay to a wavelength division multiplexing (WDM) signal so that all of its WDM components are delayed by substantially the same delay time. The OAPF has a free spectral range (FSR) that matches spectral separation between carrier wavelengths of the WDM signal. Advantageously, an optical multiplex synchronizer suitable for feeding a synchronous optical switch fabric can be implemented as an integrated waveguide circuit using a plurality of such multiplex delay units.

Multiplex delay unit

One embodiment of the invention provides an optical signal synchronizer having a plurality of optical channel synchronizers. Each optical channel synchronizer receives a respective input wavelength division multiplexing (WDM) signal and processes it to produce a corresponding output WDM signal, in which optical data packets corresponding to different carrier wavelengths are synchronized to each other regardless of the presence or absence of such synchronization in the input WDM signal. The optical signal synchronizer further has an optical multiplex synchronizer that receives the output WDM signals from the optical channel synchronizers and synchronizes them to each other and to an external reference clock without demultiplexing any of them into individual WDM components.

Optical signal synchronizer

There is provided a system and method for fabricating an optical isolator. More specifically, there is provided a fiber optical isolator comprising a first isolator stage comprising a Faraday rotator configured to adjust the polarity of a light beam, and a heat sink coupled to the Faraday rotator and configured to dissipate heat generated in the Faraday rotator by the light beam.

System and method for fabricating an optical isolator

In accordance with the invention, a variable optical delay line with a large continuous tuning range comprises an incremental variable delay line to provide delay selected from a sequence of incrementally differing delays and a continuous variable delay line to provide a continuously variable delay over a range encompassing a delay increment in the first variable delay line. In a preferred embodiment, the first variable delay line comprises an array of delay paths where each path is curved differently from the others to provide an incrementally different delay. The second variable delay line is a tunable delay path continuously tunable over the delay increment of the first.

Variable optical delay line with a large continuous tuning range

In accordance with the invention, a high-resolution variable optical delay line comprises an optical switch, such as an optical micromechanical mirror switch, and an array of delay fiber paths. Each delay fiber path in the array comprises a region where the fiber is curved differently from the other fibers in the region and a reflector. Each fiber path advantageously comprises other regions where the fiber is essentially parallel to the other fibers in the region. Each fiber is curved differently from the others in order that the fiber paths each provide a different delay.

Variable optical delay lines and methods for making same

In accordance with the invention, the optical power level in an optical waveguide is monitored by enclosing a length of the waveguide within an insulated cavity of comparable length and cross section, measuring a first temperature T within the cavity, measuring a second temperature T outside the cavity and deriving from the difference, T &minus;T , a measure of the optical power level. Exemplary apparatus for monitoring the optical power level in an optical waveguide comprises a substrate with an insulated groove for receiving an optical fiber, an insulated lid for sealing the fiber within the groove, and internal and external temperature sensors.

Method and apparatus of monitoring optical power level in waveguiding structures

In accordance with the invention, a waveguide laser or amplifier having a peak absorption wavelength is provided with pump emitters having wavelengths deliberately offset from the peak absorption wavelength. The offset wavelengths of the emitters are chosen to enhance the thermal stability of the laser or amplifier. In one exemplary embodiment, the laser or amplifier is pumped by a bimodal distribution of emitters.

Waveguide lasers and optical amplifiers having enhanced thermal stability

An optical communication system which conserves electrical power is disclosed. Electrical power is conserved in the optical communication system by coupling a splitter to an optical amplifier. The optical amplifier is configured to receive optical signals as well as pump light. The splitter provides a portion of the pump light used in the optical amplifier to other devices (e.g., optical amplifiers, filters, modulators) of the optical communication system. Providing a portion of the pump light used in the optical amplifier to other devices in the optical communication systems conserves electric power by reducing the total electrical power needed to operate the optical communication system.

Splitter for use with an optical amplifier

In accordance with the invention, a pumped waveguide device comprising a pump waveguide and an active waveguide is provided with a pump power monitor by disposing between the pump source and the active waveguide, an indicator waveguide having a core doped with a material sensitive to the pump light. For example the material can fluoresce in response to pump light or absorb pump light and generate heat. Pump power is then accurately measured by the fluorescence or heat from the indicator waveguide. Since the fluorescence or heat is generated in the doped core, the measurement is sensitive to the pump power that will enter the active waveguide and is relatively insensitive to changes in mode distribution. Exemplary embodiments include monitored cladding pumped fiber lasers, amplifiers and light sources.

Optical waveguide lasers and amplifiers with pump power monitors

A method and article for monitoring and controlling power drift in the output of a diode array is described. The diode array is used, for example, as a light pump for a fiber laser. In one embodiment, an improved fiber laser includes the light pump, which launches light into a laser cavity. The fiber laser further includes a sampler operable to receive at least a portion of the light before it is launched into the laser cavity. The sampled portion represents a known fraction of the total light signal generated by the light pump. In some embodiments, the sampled light is directed, via the sampler, to a photodetector. The photodetector converts the sampled light into a first electrical signal and delivers it to a processor. The processor is operable to compare the electrical signal with a set-point signal representative of a desired power output of the sampled portion of the launched light. To the extent that a differential exists between the set point signal and the first electrical signal, the desired optical power is not being launched into the lasing cavity. If such a differential exists, the processor generates and sends a control signal to a controllable current source. The control signal is operable to increase or decrease the current delivered from the controllable current source to the light pump to correct power drifts in light pump output.

Article for detecting power drift in the putout of a diode array source

The performance of optical fiber Raman devices can be increased by substitution of a broadband reflector (typically a multilayer dielectric mirror) for some of the narrowband reflectors (typically fiber Bragg gratings) that are conventionally used to define the optical cavities of the device. The device exemplarily is a Raman laser or amplifier, and in preferred embodiments a broadband reflector reflects all the Stokes-shifted wavelengths, such that the cavities are defined by the single broadband reflector and by a multiplicity of appropriately selected narrowband reflectors. Optionally the broadband reflector also serves to reflect the pump radiation.

Growing community of inventors

Princeton, NJ, United States of America

Jane Deborah LeGrange