Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An apparatus and method for spectral dispersion compensation in an optical communication network are disclosed. In one embodiment, the invention comprises an optical medium having a signal distributed over a plurality of wavelengths, a demultiplexer adapted to receive the plurality of wavelengths and divide the plurality of wavelengths into individual wavelengths, and a plurality of dispersion compensation elements each adapted to receive a wavelength. The dispersion compensation elements alter the timing of each wavelength, where the plurality of dispersion compensation elements operates on all wavelengths simultaneously. The invention also comprises a multiplexer adapted to receive each individual wavelength and combine the individual wavelengths onto the optical medium.

Abstract: A method of making an optical device to wavelength multiplex/de-multiplex light signals by altering the refractive index of regions within a material is disclosed. A substrate is formed from a material having a refractive index that can be altered by a process. At least one region within the substrate is subjected to the process, thereby altering the refractive index of the substrate within that region. An optical component of the multiplexer/de-multiplexer is formed by or includes the altered region. Also disclosed is an optical multiplexer/de-multiplexer device that includes an optical component that includes a region within a substrate, in which the region has an altered refractive index.

Abstract: The optical multiplexer/demultiplexer comprises an input/output channel array, a diffractive element, an arraying device and a converging element. The input/output channel array is located adjacent an optical axis and includes input/output channels arrayed in a first direction, orthogonal to the optical axis, at a predetermined pitch. The diffractive element is arranged to receive light from the input/output channel array at a location separated from the input/output channel array along the optical axis. The diffractive element diffracts the light to array the light wavelength-dependently in a second direction, different from the first direction. The arraying device receives light diffracted by the diffractive element and arrays the light in the first direction at a pitch equivalent to the predetermined pitch. The converging element is located along the optical axis between the diffractive element and either or both the arraying device and the input/output channel array.

Abstract: 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.

Abstract: A demultiplexer system having an interleaver for dividing the incoming wavelength-division multiplexed (WDM) signal into interleaved WDM signals and a single demultiplexing device for demultiplexing the de-interleaved WDM signals into single-channel signals is disclosed. Because a single demultiplexing device is used, size and cost savings can be realized.

Abstract: 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.

Abstract: An interleaver implemented using a directional separator and Bragg grating sections is disclosed. Wavelength division multiplexed (WDM) signal enters the interleaver and is directed from the input medium to a first output medium. The first output medium includes Bragg grating segments designed to reflect alternating channels of the WDM signal. The reflected channels are directed to a second output medium.

Abstract: An optical demultiplexer is implemented using a dispersive means and a photodetector array. An incoming wave division multiplexed (WDM) signal is dispersed into its component optical channels, and each optical channel is converted into its corresponding electrical signal. Outputs of the optical multiplexer are electrical signals.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.