Agilent Technologies, Inc.

Hewlett-packard Company

Other

Kenneth R Wildnauer

James R Stimple

Rene P Helbing

Barry G Broome

William Richard Trutna

Joseph Newhall West

Thomas L Mikes

Gary Wang

Peter Egerton

John D Knight

Annette Claire Grot

Roger Lee Jungerman

Zoltan Azary

Steven D Warwick

Ian Hardcastle

Zoltana D Azary

Paul S Bussard

A data conversion system acquires samples of low frequency signal components of an applied analog signal at a first data conversion rate and samples of high frequency signal components of the applied analog signal at a second data conversion rate that is higher than the first data conversion rate. The data conversion system applies a first correction filter to the acquired samples of the low frequency signal components to provide a first filtered signal and applies a second correction filter to the acquired samples of the high frequency signal components to provide a second filtered signal. The data conversion system interpolates the first filtered signal to provide an interpolated signal, and sums the interpolated signal with the second filtered signal to provide an output signal.

Data conversion system

Devices and methods for processing multi-wavelength light beams and the single-wavelength components of such light beams are disclosed. In accordance with some embodiments, a spectral filter includes collimating and focusing optical elements, an apodizing filter, a diffraction grating, and a spatial filter. The collimating optical element collimates an input light beam while the apodizing filter spatially filters this beam. In general, the apodizing filter includes a range of transmissivity that varies according to a distance from a predetermined location on the apodizing filter. The diffraction grating diffracts the input beam which is focused by the focusing optical element onto the spatial filter to generate a filtered output beam. Embodiments of the invention may be employed as spectral filters, optical spectrum analyzers, optical mutiplexers, optical de-multiplexers, and the like.

Method and apparatus to improve the dynamic range of optical devices using spatial apodization

The optical waveguide device comprises two optical waveguides and an optical coupler extending between the adjacent ends of the waveguides. The optical coupler comprises material that includes a waveguide region. The waveguide region has a shape defined by overlapping cones of light emitted from the ends of the optical waveguides. In the optical alignment method, first and second optical waveguides are axially aligned, leaving a gap between their adjacent ends. The gap is filled with material having a refractive index capable of being increased by exposing the material to light. The material is exposed to conical beams of light emitted from the adjacent ends of the waveguides. Exposing the material increases the refractive index of the material in a region in which the beams of light overlap. The resulting refractive index difference prevents light from diverging as it propagating across the gap between adjacent ends of the optical waveguides.

Optical alignment of optical waveguides

Systems and methods for making a self-aligning optical system are provided, Briefly described, in architecture, one such system for making an optical system, among others, can be implemented as follows. The system includes a grating substrate supporting a holographically-formed diffraction grating and an array mount for defining relative locations of point sources of light. The array mount contains recording points that define locations of point sources of recording light used to illuminate the grating substrate during fabrication of the holographically-formed diffraction grating and use points that define locations of light apertures used in operation of the holographically-formed diffraction grating. Other systems and methods are also provided.

Self-aligning holographic optical system and related methods

The tunable optical filter includes an elastic substrate, a diffractive element in the elastic substrate, an actuator for stretching the elastic substrate to control the pitch of the diffractive element, a first optical path and a second optical path. The diffractive element optically couples the second optical path to the first optical path at an optical frequency determined by the pitch of the diffractive element.

Tunable optical filter based on a physically-deformable diffractive element

An apparatus for optically shifting the frequency of an input signal beam includes a first Raman medium that receives an input signal beam, a first pump beam, and a first reference beam to responsively generate an intermediate signal beam comprising a Raman sideband of the first Raman medium. A second Raman medium is optically coupled in series with the first Raman medium. The second Raman medium receives the intermediate signal beam, a second pump beam, and a second reference beam to responsively generate an output signal beam comprising a Raman sideband of the second Raman medium. The generated output signal represents the input signal that is shifted in frequency by a frequency shift that corresponds to the frequency difference between the first and second reference beams.

Apparatus and method for shifting the frequency of an optical signal by two-stage Raman scattering

The optical module optically aligns two adjacently located optical components. The optical module comprises a substrate and at least one pre-alignment groove formed therein for coarsely aligning the two optical components. The optical components are seated in the at least one groove with a gap between them. The optical module further comprises a waveguide core located in the gap between the two optical components. The waveguide core extends from a light-guiding portion of one optical component to a light-guiding portion of the other optical component and guides light from one optical component to the other.

Optical module with alignment waveguide

Optical wavelength reference apparatus with wide wavelength range. Illuminated by a wideband source, a first reference such as absorption lines in a gas cell is used as a transfer standard, calibrating the response of the secondary reference over the range of the first reference. The performance of the second reference is extrapolated to a wider wavelength range, retaining the stability and accuracy characteristics of the first reference. Suitable secondary devices include etalons such as Fabry-Perot filters and Mach-Zehnder interferometers.

Extended wavelength calibration reference

An optical source generates optical signals as a result of varying polarization states to achieve oscillation within an optical loop. The optical signals have narrow spectral width and the optical source is tuneable, so that optical components stimulated by the optical signals can be characterized over a predefined wavelength range with high wavelength resolution. The optical loop includes an optical gain element, a tuneable filter, and a polarization scrambler that provides a varying polarization transfer function. The optical gain element has sufficiently high gain within the passband of the tuneable filter and the polarization transfer function is sufficiently varied to attain oscillation within the optical loop, thereby generating the optical signals. The varying polarization transfer function of the polarization scrambler produces a corresponding variation in the polarization of the generated optical signals, which are coupled from the optical loop to an output.

Polarization randomized optical source having short coherence length

Improved calibration of optical wavelength measuring instruments. In a first embodiment, improved calibration is achieved in an optical wavelength measuring instrument by performing calibration measurements at a plurality of known wavelengths and using an average calibration constant derived from the plurality of measurements. In a second embodiment, improved calibration is achieved by performing calibration measurements at a plurality of known wavelengths and calculating a linear or higher order calibration model, or a periodic model. These approaches may be extended by segmenting the wavelength range and using different calculated calibration values, or different calibration models, for each segment.

Multipoint wavelength calibration technique

Wavelength reference standard using multiple gasses and calibration methods using same. A wavelength reference using absorption lines of multiple gasses provides stable reference wavelengths over multiple regions of interest of the optical spectrum. The gasses may be in separate cells or combined in one cell. Improved calibration using the reference is achieved by performing calibration measurements at a plurality of known wavelengths and using an average calibration constant derived from the plurality of measurements. In a second embodiment, improved calibration is achieved by performing calibration measurements at a plurality of known wavelengths and calculating a higher order calibration model, such as a least-squares linear fit. Both approached may be extended by segmenting the wavelength range and using calculated calibration values for each segment.

Wavelength reference standard using multiple gases

A double-pass scanning monochromator for use in an optical spectrum analyzer includes an input optical fiber for emitting an input light beam, a diffraction grating for diffracting the input light beam to produce a spatially dispersed light beam, a slit for passing a selected portion of the dispersed light beam, a motor for rotating the diffraction grating, a shaft angle encoder for sensing grating position, and an output optical fiber. The light that passes through the slit is directed to the diffraction grating and is recombined by the diffraction grating to produce an output light beam. The light beam to be analyzed is incident on the diffraction grating during first and second passes. A polarization rotation device rotates the polarization components of the light beam by 90.degree. between the first and second passes so that the output of the monochromator is independent of the polarization of the input light beam. The output optical fiber is translated by a micropositioning assembly in a plane perpendicular to the output light beam during rotation of the diffraction grating to automatically track the output light beam and to provide optical chopping.

Diffraction grating position sensing and control for a scanning

A double pass scanning monochromator for use in an optical spectrum analyzer includes an input optical fiber for emitting an input light beam, a diffraction grating for diffracting the input light beam to produce a spatially dispersed light beam, a slit for passing a selected portion of the dispersed light beam, a motor for rotating the diffraction grating, a shaft angle encoder for sensing grating position, and an output optical fiber. The light that passes through the slit is directed to the diffraction grating and is recombined by the diffraction grating to produce an output light beam. The light beam to be analyzed is incident on the diffraction grating during first and second passes. A polarization rotation device rotates the polarization components of the light beam by 90.degree. between the first and second passes so that the output of the monochromator is independent of the polarization of the input light beam. The output optical fiber is translated by a micropositioning assembly in a plane perpendicular to the output light beam during rotation of the diffraction grating to automatically track the output light beam and to provide optical chopping.

Optical spectrum analyzer having double-pass monochromator

An optical spectrum analyzer is provided with a user selectable sensitivity. Required operating parameters are set in response to user selection of sensitivity to permit measurement of an input light beam at the selected sensitivity. Setting the required parameters includes setting a required gain of a video channel to permit measurement of a specified maximum light signal and to provide the selected sensitivity, setting a required video bandwidth of the video channel to provide the selected sensitivity at the required gain of the video channel and setting a sweep rate to provide the selected sensitivity at the required video bandwidth. When the normal bandwidth of the video channel is not adequate to provide the selected sensitivity, the electrical signal is passed through a digital filter having a filter coefficient set to provide the required video bandwidth. A peak detector is incorporated in the video channel to accurately measure signal amplitudes in a fast scanning condition.

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Santa Rosa, CA, United States of America

Kenneth R Wildnauer