Agilent Technologies, Inc.

Other

William Ian McAlexander

Douglas Michael Baney

Tun Sein Tan

Mohan Gurunathan

Gregory Douglas VanWiggeren

Mark Andrew Troll

Richard Paul Tella

Richard D Pering

Bita Ghaffari

Doug Baney

Randall G Hulet

Curtis Charles Bradley

Jordan Mitchell Gerton

Kevin Edwin Strecker

Jeffrey J Tollett

Stephen Calvin Moss

Charles Ackley Sackett

An apparatus and method for measuring the attenuation and dispersion introduced by a sample into an optical signal are disclosed. The apparatus includes a chirped light source, a beam splitter and an optical detector. The beam splitter splits the optical signal generated by the light source into a reference optical signal and a sample optical signal. The sample and reference optical signals are mixed on the detector after the sample optical signal has traversed an experimental sample thus generating a signal having an AC component related to an attenuation and a dispersion introduced by the experimental sample. The optical paths traversed by the reference and sample optical signals between the beam splitter and the detector are chosen such that the reference optical signal and the sample optical signal overlap in time but do not arrive at the optical detector at the same time.

Spectrographic system utilizing a chirped, pulsed optical source

A receiver and method for using the same to process optical signals is disclosed. The receiver includes an optical coupler and a polarization dependent beam splitter. The optical coupler combines an input signal and a local oscillator signal into a first combined signal. The optical coupler includes a polarization filter that operates on the local oscillator to provide a linearly polarized signal having a predetermined LO polarization direction.

Polarization diverse optical receiver using a polarization-dependent beam splitter

In one embodiment, a method determines the spectral content of an optical signal. Specifically, the optical signal and an optical local oscillator (LO) signal are provided to inputs of an optical hybrid (e.g., an N&#xd7;N optical coupler where N is greater than two). The phase-diverse components from the optical hybrid are photodetected allowing for mixing of the optical signal and the optical local oscillator. Bandpass filtering is performed to eliminate or reduce relative intensity noise (RIN). The filtered signals are mixed with an electrical LO signal. A quadrature representation of a phase-diverse heterodyne signal is generated from signals from the mixing. The negative image and the positive image from the quadrature representation are separated. The spectral content of the optical signal is determined from the images.

Systems and methods for determining the spectral content of an optical signal

A phase-diverse coherent optical spectrum analyzer is presented. An optical receiver receives a first input signal and a second input signal, and produces at least a first output signal, a second output signal, and a third output signal based on mixing the first input signal and the second input signal. A processing unit isolates heterodyne components from the first output signal, the second output signal and the third output signal, wherein the heterodyne components comprise a first signal and a second signal that represent the phase-diverse nature of the optical mixing process. Phase diversity of the heterodyning between the first input signal and the second input signal is achieved by the coherent optical spectrum analyzer.

Phase-diverse coherent optical spectrum analyzer

Embodiments in accordance with the invention provide an optical spectrum analyzer. The optical spectrum analyzer includes a receiver for receiving an optical local oscillator signal and an unknown optical signal. The receiver outputs three or more phase-diverse heterodyne signals. The phase-diverse heterodyne signals are coupled to a phase quadrature generator. The phase quadrature generator produces a first and second phase quadrature signals that are ninety degrees out of phase with respect to each other. The first and second phase quadrature signals are coupled to a complex signal generator. The complex signal generator produces a complex signal having a positive and negative image. A measurement processing unit determines the phase of the unknown optical signal from the relative difference of the phase of the positive and negative image of the complex signal.

Spectral phase measurement using phase-diverse coherent optical spectrum analyzer

An optical heterodyne detection system includes an attenuator for attenuating an input signal before the input signal is combined with a local oscillator signal. An optimal attenuation level for the input signal, which improves the signal to noise ratio of the heterodyne beat signal, is determined by obtaining a base measurement of an output signal in response to the local oscillator signal and in the absence of the input signal, obtaining sample measurements of the output signal in response to the input signal as a function of different attenuation levels, and determining the optimal attenuation level as a function of the base measurement and the sample measurements. A minimum attenuation level for the input signal, which protects receiver photodetectors from being saturated or damaged, is determined by setting an initial attenuation level and gradually reducing the attenuation level until the voltage limit of the photodetectors is reached.

Heterodyne based optical spectrum analysis with controlled optical attenuation

A compact, broadband laser source is realized by using a rare earth dopant to define a laser gain spectrum and by using holographic imprinting techniques to form a wavelength selection element for selecting a particular wavelength from within the gain spectrum. Artificial broadening of the gain spectrum can be achieved by establishing varied (e.g., randomized) domains of space charge within a rare earth-doped laser gain medium. Compactness can be enhanced by fabricating the laser gain medium and wavelength selection elements within a single member, such as a photorefractive crystal substrate. Flexibility in the selection of a wavelength can be obtained by holographically imprinting multiple sets of wavelength selection elements.

Rare earth-doped medium with photorefractive grating as compact laser source

A method for determining at least one optical property of an optical device comprises providing an optical input signal that includes first and second signal components that are modulated at first and second frequencies, respectively, and that have first and second polarization states, respectively. The optical input signal is passed to an optical device. An optical output signal from the optical device is separated into first and second output signals that have third and fourth polarization states, respectively. The first and second output signals are each compared with reference signals at the first and second frequencies to provide four phase shift and amplitude measurements that can be used to determine the at least one optical property of the optical device as a function of wavelength.

Single sweep phase shift method and apparatus for measuring chromatic and polarization dependent dispersion

Neutral particles, such as atoms and molecules, transported along a path having at least one curved region are selectively conveyed or filtered according to each particle's velocity by generating an inhomogeneous magnetic field across a cross-section of the path. The neutral particles may be transported through a physical tube or simply through the region defined by the magnetic field. The path may have more than one curved region and may additionally have one or more straight regions. The magnetic field may be generated for example by homogeneously or inhomogeneously magnetized permanent magnets or by current carrying elements. The magnetic elements may additionally be used in conjunction with at least one piece of a high permeability magnetic material for focussing or containing the magnetic field.

Growing community of inventors

Redwood City, CA, United States of America

William Ian McAlexander