Abstract: Frequency synthesis-based optical frequency domain reflectometry method and system are disclosed. The method is to implement optical frequency reflectometry and comprises: performing an electro-optic modulation and an acousto-optic modulation on a local light to obtain an optical pulse; inputting the optical pulse as a detection pulse optical signal to a test optical fiber; and detecting an obtained Rayleigh backscattered optical signal under coherent detection with the local light, and then performing a photoelectric conversion and a demodulation, wherein: the electro-optic modulation is performed by using a single frequency signal; the acousto-optic modulation is performed by using a pulse signal; and the optical pulse is obtained by simultaneously sweeping multiple frequency components of an optical comb signal which is obtained by the electro-optic modulation.

Abstract: This invention relates to the field of laser technology and more particularly to the ultra-short pulse generation methods and generators.

Abstract: An optical coherence analysis system uses a laser swept source that is constrained to operate in a stable mode locked condition by modulating a drive current to the semiconductor optical amplifier as function of wavelength or synchronously with the drive voltage of the laser's tunable element based on stability map for the laser.

Abstract: A fast switching arbitrary frequency light source for broadband spectroscopic applications. The light source may operate near 1.6 um based on sideband tuning using an electro-optic modulator driven by an arbitrary waveform generator. A Fabry-Perot filter cavity selects a single sideband of the light source. The finesse (FSR/??FWHM) of the filter cavity may be chosen to enable rapid frequency switching at rates up to 5 MHz over a frequency range of 40 GHz (1.3 cm?1). The bandwidth, speed and spectral purity are high enough for spectroscopic applications where rapid and discrete frequency scans are needed. Significant signal-to-noise advantages may be realized using the rapid and broadband scanning features of this system in many areas of spectroscopy, e.g., process monitoring and control, reaction dynamics, and remote sensing (e.g., greenhouse gas monitoring, biological/chemical agent screening).

Abstract: The present disclosure provides a procedure to obtain the absorption profiles of molecular resonance with ANSOM. The method includes setting a reference field phase to ?=0.5 ? relative to the near-field field, and reference amplitude A?5|?eff|. The requirement on phase precision is found to be <0.3 ?. This method enables ANSOM performing vibrational spectroscopy at nanoscale spatial resolution.

Abstract: A method of manufacturing a variable wavelength interference filter includes forming an electrostatic gap forming groove, a wiring forming groove extending from the electrostatic gap forming groove to an outer peripheral edge of the chip region, and an air communication groove through which the wiring groove forming groove communicates with the outside of the first substrate, in a chip region of a first substrate.

Abstract: A device representing a reflector, for example an evanescent reflector or a multilayer interference reflector, with at least one reflectivity stopband is disclosed. A medium with means of generating optical gain is introduced into the layer or several layers of the reflector. The optical gain spectrum preferably overlaps with the spectral range of the reflectivity stopband. This reflector is attached to multilayer passive cavity structure made of semiconducting, and/or dielectric, and/or metallic materials with the inserted tools of achieving wavelength selection of the optical modes. For example, volume Bragg gratings, distributed feedback gratings or patterns, using of vertical optical cavities surrounded by multilayer Bragg reflectors can be applied. The optical modes of the passive optical cavity partially penetrate into the gain region of the reflector.

Abstract: Embodiments include methods and devices for controlling the spectral profile and color gamut of light produced by an interferometric display. Such devices include illuminating a display with selected wavelengths of light. Embodiments also include a display comprising separate sections that output different predetermined colors of light. Other embodiments include methods of making the aforementioned devices.

Abstract: A method and apparatus for measuring the optical power of very weak light arriving at a receiver, by using a photon detector, are provided. A photon detector detects the presence or absence of the arrival of a photon in accordance with bias application timing. For a train of optical pulses coming in at an arbitrary timing in respective time slots, the bias application timing is sequentially shifted within the range of a time slot. Each time a shift is made, the number of photons detected is counted by a photon counter. Based on this number of photons, the optical power of the train of the optical pulses is measured.

Abstract: A wavelength tunable light source includes: an optical gain medium generating light; a wavelength tunable filter positioned on a optical path and transmitting or reflecting only a predetermined wavelength generated from and injected into the optical gain medium; a first housing where the optical gain medium and the wavelength tunable filter are mounted; and an optical fiber block providing the optical wave having the predetermined wavelength come from the wavelength tunable filter, wherein the wavelength tunable filter comprised of a dielectric thin-film filter formed by alternately stacking a first dielectric thin film layer and a second dielectric thin film layer having different refractive index.

Abstract: An integrated swept wavelength tunable optical source uses a narrowband filtered broadband signal with an optical amplifier and self-tracking filter. This source comprises a micro optical bench, a source for generating broadband light, a tunable Fabry Perot filter, installed on the bench, for spectrally filtering the broadband light from the broadband source to generate a narrowband tunable signal, an amplifier, installed on the bench, for amplifying the tunable signal. The self-tracking arrangement is used where a single tunable filter both generates the narrowband signal and spectrally filters the amplified signal. In some examples, two-stage amplification is provided. The use of a single bench implementation yields a low cost high performance system. For example, polarization control between components is no longer necessary.

Abstract: A phase difference detecting device includes a splitter for splitting laser beams into a first group which will travel along a first path and a second group which will travel along a second path, a beam selection/extraction unit for selecting, as reference light, one beam from the first group to allow it to pass therethrough, a path length changing unit for changing the length of the first path, a combining unit for combining the reference light and beams which construct the second group to produce interference light, and a detector for detecting the intensity of the interference light. The device changes the length of the first path using the path length changing unit to detect a path length which maximizes the intensity of the interference light for each of the beams which construct the second group, and determines a phase difference among the beams from the detected path length.

Abstract: According to one embodiment, an optical filter has a polarization rotator and two instances of an optical bandpass filter (OBPF). The first instance of the OBPF processes a TE-polarized component of an optical input signal to produce a first filtered signal. The polarization rotator then transforms the TE polarization of the first filtered signal into the TM polarization. The polarization rotator also transforms the polarization of a TM-polarized component of the optical input signal into the TE polarization. The second instance of the OBPF processes the resulting TE-polarized signal to produce a second filtered signal. The first and second filtered signals having TM and TE polarizations, respectively, are then combined to produce a filtered output signal.

Abstract: An object of the invention is to easily realize an optical element using an etalon type structure, capable of changing a periodic transmission wavelength characteristic in an axial direction of transmissivity, and also capable of changing a periodic characteristic with respect to wavelength. To this end, a transmission wavelength characteristics variable optical element according to the invention comprises: a light interference section including a pair of wedge shape magneto-optic crystals arranged with taper faces thereof in close contact, that can change a distance between reflecting films formed on parallel planes of the magneto-optic crystals, by relatively moving the magneto-optic crystals by movable sections, permanent magnets for applying a fixed magnet field to the pair of magneto-optic crystals, an electromagnet for applying a variable magnetic field in a direction different to the fixed magnetic field, and a variable current source controlling the current flowing into the electromagnet.

Abstract: A high extinction ratio interferometer is disclosed. The interferometer includes a first and second optical fiber each having a first end and a reflective end and an optical coupler for coupling the first optical fiber and the second optical fiber between their first ends and their reflective ends. The first optical fiber provides a first optical path from the optical coupler to its reflective end and back to the optical coupler and the second optical fiber provides a second optical path from the optical coupler to its reflective end and back to the optical coupler. The second path is greater than the first path by a delay length and the first path and the second path are each less than approximately 20 cm. The interferometer finds application as a differential phase shift keyed (DPSK) demodulator, particularly useful in a satellite system employing inter-satellite communication.

Abstract: A method to reduce undesirable outgassing includes bonding at least two optical components with a bonding material and encapsulating the bonding material with a capping material. The capping material inhibits the outgassing of species that would otherwise be emitted from the bonding material to the surrounding. In one example, the bonding material is silicone and the capping material is epoxy.

Abstract: An interferometer that includes a first beam-splitting surface positioned to separate an input beam into a first beam and a second beam. A first set of optics is positioned to receive the first beam, direct it to contact a first reflector multiple times and produce a first intermediate beam. The first intermediate beam follows a nominal output path when the first reflector has a first alignment normal to the first beam prior to reflection by the first reflector. The first set of optics includes a second beam-splitting surface, a third beam-splitting surface, and a first fold optic that are positioned to reduce displacement of the first intermediate beam from the nominal output path when the first reflector has an alignment different from the first alignment.

Abstract: An optical device comprises an optical amplifier to amplify optical signals, optical pumps coupled to and providing optical pump power to least one amplifying stage of the optical amplifier, so as to produce gain in the said optical amplifier and, a tunable optical filter coupled to the optical amplifier. The optical filter changes the gain slope of the optical amplifier in response to a change in a single parameter of the optical filter. The optical amplifier also includes at least one controller adjusting said single parameter of the optical filter and controlling the optical pumps.

Abstract: An optical device including an optical amplifier to amplify optical signals received through an optical input, and to supply the amplified optical signals from an optical output, and an optical filter coupled to the optical amplifier. The optical filter changes the gain slope of the optical amplifier in response to a change in a single parameter of the optical filter. The single parameter may be a change in a central wavelength of the optical filter function. The optical filter preferably has a parabolic spectral function. The single parameter may be varied as a function of temperature such that the variable optical attenuator compensates for variations in the gain spectrum of the optical amplifier that occur as a function of operating temperature.

Abstract: This invention relates to invention relates to a method for filtering and a variable slope optical filter for in-line use with an optical amplifier signal. The filter has a wavelength response that is substantially linear in slope within a band of operation wavelengths of the amplifier; the slope of the filter in an operating band of wavelengths is between zero and a only one of a positive or negative number; furthermore the filter has an amplitude response that has an opposite and counter slope as a function of wavelength to that of a gain tilt of the amplifier within the operation band of wavelengths. Relative movement between the filter and the optical amplifier signal is provided to vary the slope of the filter by means of varying the amplitude wavelength response of the filter.