Lucent Technologies Inc.

Clyde George Bethea

Gerald Nykolak

Laura Ellen Adams

Tawee Tanbun-Ek

Roosevelt People

Lars Erik Eskildsen

John Phillip Franey

Won-Tien Tsang

Arthur Mike Sergent

Wei-Chiao William Fang

Timothy Lloyd Pernell

Rossevelt People

Techniques and systems for monitoring of optical signals are described. Each of a plurality of optical signals is supplied to an optical port. A port signal is generated based on each of the optical signals and each of the port signals is subjected to a time delay to create a time delayed signal, with a different time delay being present in each of the time delayed signals. The time delayed signals are multiplexed to create a multiplexed signal comprising a plurality of multiplexed signal components, each component corresponding to one of the time delayed signals and exhibiting a time delay characterizing the corresponding time delayed signal. A desired one or ones of the multiplexed signal components are selected by analysis or display by specifying a time delay present in the time delayed signal represented by the desired component, and selecting a signal component exhibiting the specified time delay.

System and method for an optical signal monitor

A reel for storing optical fiber is disclosed that significantly reduces the torsional force applied to optical fiber as the fiber is being wound onto the reel for storage. The optical fiber reel comprises two spindles that are offset with respect to the rotational center of the reel. Such an arrangement causes the fiber to be wound onto the reel in a substantially linear fashion, thus preventing the torsional force and resulting twisting that cause micro-cracks to develop. The spindles are of a sufficiently large diameter to facilitate operational use of the fiber while stored on the spindle without increasing the attenuation of signals that could result from the use of a smaller diameter spindle.

Method and apparatus for operational low-stress optical fiber storage

A method and apparatus are disclosed for suppressing interference in a radio frequency (RF) communication system using active shielding techniques. An opposing neutralizing signal is applied to actively neutralize stray signals in a microwave communication environment. An interfering or stray signal is detected using a sensing antenna, and the opposing neutralizing signal is generated in response thereto. The opposing neutralizing signal is applied to a signal neutralizing shield to shield any desired components or devices. The opposing neutralizing signal is approximately 180 degrees out of phase, and of equal magnitude to the detected interfering signal. A phase shifter/null feedback device receives the detected stray signal, if any, and adaptively adjusts the phase and magnitude of the opposing neutralizing signal. In one embodiment, the phase shifter/null feedback device includes an integrator that generates a DC value that is proportional to the energy of the interfering signal. The DC value is applied to a voltage controlled oscillator (VCO) using known feedback techniques to adjust the phase or magnitude, or both, of the opposing neutralizing signal and to thereby minimize the DC value.

Method and apparatus for suppressing interference using active shielding techniques

A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A tuning voltage applied to the composite reflector induces refractive index changes, thereby allowing the center wavelength to be altered. A dither signal applied the composite reflector broadens the spectrum of the laser output, thereby reducing SBS in fiber optic systems

Optical system for reduced SBS

WDM system for reduced SBS

A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A voltage applied to the composite reflector induces a quantum confined stark effect, thereby allowing the wavelength to be altered. In one embodiment, the current drive to the active region and the shape of the first waveguide (e.g., a raised-sine function) are mutually adapted so that N longitudinal modes have essentially the same threshold gain and so that the DFB region spanned by the first waveguide is segmented into N zones, each zone providing optical feedback at a different wavelength corresponding to a different longitudinal mode.

Broadband tunable semiconductor laser source

In a WDM fiber-optic network, a unique laser transmitter enables signals to be routed at three hierarchical levels: at one level discrimination among signal paths is based on N WDM wavelength channels, at another level discrimination is based on m AM subcarrier frequency channels, and at a third level discrimination is based on n FM subcarrier frequency channels. Thus, a total of Nmn distinguishable optical channels can be accommodated and a like number of users served. The laser transmitter comprises a broadband, tunable semiconductor laser which includes an intracavity, integrated composite reflector to which a tuning voltage and a FM dither signal are applied, an intracavity gain section to which drive current is applied, and an extracavity, integrated electroabsorption modulator to which an information (e.g., data, voice, video) signal and an AM dither signal are applied. The tuning voltage provides coarse wavelength tuning among N WDM channels, whereas the FM dither signal produces an additional m channels via FM-SCM. The AM dither likewise produces an additional n channels via AM-SCM.

Sub-carrier multiplexing in broadband optical networks

A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A tuning voltage applied to the composite reflector induces refractive index changes, thereby allowing the center wavelength to be altered. A dither signal applied the composite reflector broadens the spectrum of the laser output, thereby reducing SBS in fiber optic systems.

Laser transmitter for reduced SBS

A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A tuning voltage applied to the composite reflector induces a quantum confined stark effect, thereby allowing the center wavelength to be altered. A pre-chirp signal applied the composite reflector reduces signal distortion in fiber optic systems.

Growing community of inventors

Franklin, NJ, United States of America

Clyde George Bethea