Abstract: An integrated wavelength selectable photodiode includes a device package having an input that receives an optical signal. A set-and-hold, thermally tunable thin-film filter is positioned in the device package and includes an input that is optically coupled to the input of the device package. The set-and-hold, thermally tunable thin-film filter passes light with a predetermined optical bandwidth to an output. An optical element collimates an incident optical beam onto the input of the set-and-hold, thermally tunable thin-film filter. A detector is positioned in the device package and includes an input that is optically coupled to the output of the set-and-hold, thermally tunable thin-film filter. The detector detects data received by the integrated wavelength selectable photodiode.

Abstract: A method for estimating optical power in an optical channel includes determining a tunable filter full-width, FWF, by measuring a response of the tunable filter to a known signal and mapping the response to frequency. A portion of an optical channel is coupled to an input of the tunable optical filter. A peak power response, PR, and a full width tunable filter response, FWR, to the optical channel are determined by measuring a response of the tunable filter to the optical channel and mapping the response to frequency. A signal power, PS, is then calculated from the peak power response, PR, and a ratio of the full width tunable filter response, FWR, to the tunable filter full-width, FWF.

Abstract: Spectrally filtering at least one input beam includes dispersing spectral components of at least one input beam at different respective angles in a spectral plane; changing at least some of the angles of the propagation axes of the dispersed spectral components so that the maximum angular separation among the propagation axes of the spectral components changes; receiving a plurality of the dispersed spectral components incident on a reflective surface at a location at which the central rays of each of the spectral components are incident at different points on the reflective surface; and tilting the reflective surface to select at least one and fewer than all of the received spectral components to be directed to a selected output path.

Abstract: A tunable laser includes an optical cavity comprising a first and second mirror. A gain medium is positioned in the optical cavity that generates stimulated emission in the optical cavity when biased. A thermally tunable optical filter is positioned in the optical cavity that is heated to a temperature that selects a desired optical mode of the optical cavity. A thermally tunable optical phase retarder is positioned in the optical cavity that is heated to a temperature which changes an optical path length in the optical cavity by an amount corresponding to a resonant frequency of the tunable optical filter so that a phase-matching condition of the optical cavity is shifted to the desired optical mode of the optical cavity selected by the thermally tunable optical filter.

Abstract: A thermally tunable Fabry-Perot optical filter includes a single crystalline sheet resistance heater layer. A single crystalline semiconductor spacer layer is positioned proximate to and in thermal communication with the single crystalline sheet resistance heater layer. A first distributed Bragg reflector is positioned proximate to a first surface of the single crystalline semiconductor spacer layer. A second distributed Bragg reflector is positioned proximate to a second surface of the single crystalline semiconductor spacer layer.

Abstract: An optical spectrum monitor includes a tunable optical detector that receives optical channel monitoring signals from an optical channel and receives a control signal that selects a frequency of an optical channel monitoring signal for detection. The tunable optical detector detects the optical channel monitoring signal selected by the control signal and generates an electrical signal related to a power of the detected optical channel monitoring signal. A processor analyzes a plurality of differences between selected optical channel monitoring frequencies and their corresponding ITU frequencies and then generates the control signal at the output that corrects for at least one of systematic band offset and systematic band tilt in the optical channel monitoring frequency.

Abstract: An optical receiver includes an optical detector that generates a photocurrent at an output. A transimpedance amplifier generates an amplified voltage signal corresponding to the photocurrent generated by the optical detector. An offset voltage generator generates an offset voltage that biases the voltage signal generated by the transimpedance amplifier. A switch having a first input electrically connected to the output of the transimpedance amplifier and a second input electrically connected to the output of the offset voltage generator switches between the offset voltage and the voltage signal generated by the transimpedance amplifier.

Abstract: Spectrally filtering at least one input beam includes: dispersing spectral components of at least one input beam at respective angles in a spectral plane; changing at least some of the angles of the propagation axes of the dispersed spectral components so that a plurality of the spectral components reflect from a single reflective surface; and tilting the reflective surface to select at least one and fewer than all of the received spectral components to be directed to an output spatial mode.

Abstract: For spectrally filtering at least one input beam, a first reflective element is configured to tilt to multiple tilt orientations that each corresponds to a different angle of propagation of at least one input beam. One or more optical elements are configured to change at least some of the relative angles of propagation of the input beam for different tilt orientations of the first reflective element. A spectrally dispersive element is configured to receive the input beam at a location at which the central ray of the input beam is incident at different points on the spectrally dispersive element for each of the tilt orientations, and configured to disperse spectral components of the input beam at different respective angles in a spectral plane. The first reflective element is configured to tilt to select at least one and fewer than all of the dispersed spectral components to be directed to a selected output path.

Abstract: A method for estimating optical power in an optical channel includes determining a tunable filter full-width, FWF, by measuring a response of the tunable filter to a known signal and mapping the response to frequency. A portion of an optical channel is coupled to an input of the tunable optical filter. A peak power response, PR, and a full width tunable filter response, FWR, to the optical channel are determined by measuring a response of the tunable filter to the optical channel and mapping the response to frequency. A signal power, PS, is then calculated from the peak power response, PR, and a ratio of the full width tunable filter response, FWR, to the tunable filter full-width, FWF.

Abstract: An optical signal-to-noise ratio monitor includes a demodulator comprising an input that receives at least a portion of a phase modulated optical signal. The monitor also includes a delay interferometer with a periodic phase control that sweeps a differential delay of one arm of the interferometer through a plurality of differential optical phase shifts. The demodulator converts phase modulated optical signals to intensity modulated optical signals. A tunable optical filter continuously scans a transmission wavelength over a desired wavelength range in a time that allows more than one wavelength to be transmitted through an output of the tunable filter for each of the plurality of differential optical phase shifts. An optical detector detects the filtered optical signal and generates a corresponding electrical demodulation signal at an output. A processor determines an optical signal-to-noise ratio for the more than one wavelength of the optical signal.

Abstract: An integrated wavelength selectable photodiode includes a device package having an input that receives an optical signal. A set-and-hold, thermally tunable thin-film filter is positioned in the device package and includes an input that is optically coupled to the input of the device package. The set-and-hold, thermally tunable thin-film filter passes light with a predetermined optical bandwidth to an output. An optical element collimates an incident optical beam onto the input of the set-and-hold, thermally tunable thin-film filter. A detector is positioned in the device package and includes an input that is optically coupled to the output of the set-and-hold, thermally tunable thin-film filter. The detector detects data received by the integrated wavelength selectable photodiode.

Abstract: An optical device including: a glass substrate; a crystalline silicon layer bonded to the glass substrate; and a thermally tunable thin-film optical filter fabricated on top of the crystalline silicon layer.

Abstract: An optical spectrum monitor includes a tunable optical detector that receives optical channel monitoring signals from an optical channel and receives a control signal that selects a frequency of an optical channel monitoring signal for detection. The tunable optical detector detects the optical channel monitoring signal selected by the control signal and generates an electrical signal related to a power of the detected optical channel monitoring signal. A processor analyzes a plurality of differences between selected optical channel monitoring frequencies and their corresponding ITU frequencies and then generates the control signal at the output that corrects for at least one of systematic band offset and systematic band tilt in the optical channel monitoring frequency.