Abstract: An optical dispersion compensator including: a spacer element having a top surface and a bottom surface; a thin film, multi-layer mirror formed on the top surface of the spacer element, the thin film mirror having a thermally tunable reflectivity; a highly reflective mirror element formed on the bottom surface of the spacer element; and a heater element for controlling a temperature of the thermally tunable thin film mirror.

Abstract: An optical sensor for detecting a chemical in a sample region includes an emitter for producing light, and for directing the light through the sample region. The sensor also includes a detector for receiving the light after the light passes through the sample region, and for producing a signal corresponding to the light the detector receives. The sensor further includes a thermo-optic filter disposed between the emitter and the detector. The optical filter has a tunable passband for selectively filtering the light from the emitter. The passband of the optical filter is tunable by varying a temperature of the optical filter. The sensor also includes a controller for controlling the passband of the optical filter and for receiving the detection signal from the detector. The controller modulates the passband of the optical filter and analyzes the detection signal to determine whether an absorption peak of the chemical is present.

Abstract: A switchable optical filter including a first thin-film optical bandpass filter portion; and a second thin-film optical bandpass filter portion, wherein both the first and second thin-film optical bandpass filter portions are adjacent to each other and form parts of single integral structure, and wherein the first thin-film optical bandpass filter is thermally tunable and is characterized by a passband that shifts as a function of temperature and wherein the second thin-film optical bandpass filter is thermally non-tunable.

Abstract: According to various embodiments and aspects of the present invention, there is provided a dynamically tunable thin film interference coating including one or more layers with thermo-optically tunable refractive index. Tunable layers within thin film interference coatings enable a new family of thin film active devices for the filtering, control, modulation of light. Active thin film structures can be used directly or integrated into a variety of photonic subsystems to make tunable lasers, tunable add-drop filters for fiber optic telecommunications, tunable polarizers, tunable dispersion compensation filters, and many other devices.

Abstract: Materials suitable for fabricating optical monitors include amorphous, polycrystalline and microcrystalline materials. Semitransparent photodetector materials may be based on silicon or silicon and germanium alloys. Conductors for connecting to and contacting the photodetector may be made from various transparent oxides, including zinc oxide, tin oxide and indium tin oxide. Optical monitor structures based on PIN diodes take advantage of the materials disclosed. Various contact, lineout, substrate and interconnect structures optimize the monitors for integration with various light sources, including vertical cavity surface emitting laser (VCSEL) arrays. Complete integrated structures include a light source, optical monitor and either a package or waveguide into which light is directed.

Abstract: An optoelectronic device including a header having an upper surface and including a plurality of conducting pins extending up through the upper surface; an optical device; a tunable optical filter, wherein the optical device and the tunable optical filter are arranged in a vertical stack mounted on and extending above the upper surface of the header and wherein the tunable optical filter is electrically connected to the plurality of conducting pins; and a cap affixed to the header and along with the header defining a sealed interior containing the optical device and the tunable optical filter, wherein the cap has a top surface with a window formed therein, and wherein the window is aligned with the tunable optical filter and the optical device.

Abstract: According to various embodiments and aspects of the present invention, there is provided a dynamically tunable thin film interference coating including one or more layers with thermo-optically tunable refractive index. Tunable layers within thin film interference coatings enable a new family of thin film active devices for the filtering, control, modulation of light. Active thin film structures can be used directly or integrated into a variety of photonic subsystems to make tunable lasers, tunable add-drop filters for fiber optic telecommunications, tunable polarizers, tunable dispersion compensation filters, and many other devices.

Abstract: A method for optical stress analysis comprises the steps of directing an incident beam of polarized light to the sample to be analyzed and analyzing a light bundle exiting the sample in two detection channels extending perpendicular to one another with respect to the polarization direction, providing that the incident beam is elliptically polarized, carrying out the elliptical polarization with an elliptic shape having a comparatively large ratio of the large principal axis to the small principal axis, the direction of rotation of the elliptical polarization of the incident beam changing periodically and using two alternative states of the direction of rotation for each measurement process, adjusting the detection channels which extend perpendicular to one another corresponding to the position of the principal axes of the ellipse and carrying out the difference between two measurements consecutively with the same beam intensity of the incident beam and the same ratio of principal axes, but with opposite direc

Abstract: In one embodiment, a system for providing electrical energy to a traveling spark ignitor operating in an internal combustion engine is disclosed. The system may include a conventional ignition system connected to the ignitor and a follow-on current producer which produces a follow-on current that travels between electrodes of the ignitor after an initial discharge of the conventional ignition system through the ignitor. The system may also include a disabling element that prevents the follow-on current from being transmitted to the ignitor. The disabling element may prevent the follow-on current from being transmitted to the ignitor based upon current operating conditions of the engine. When the disabling element prevents the follow-on current from being transmitted to the ignitor the system operates in a conventional manner.

Abstract: An optical instrument may include a tunable free-space filter as a wavelength selector. That optical instrument may be an optical spectrum analyzer (OSA). Indeed, the OSA may be constructed and arranged as an optical channel monitor for wavelength-division multiplexed optical communication systems. The tunable free-space filter may be a tunable thin film filter (TTFF). The TTFF may be thermo-optically tunable. The tunable filter may be a multi-layer film structure incorporating thin film semiconductor materials. The temperature, and hence the wavelength, of the TTFF may be controlled by various heating and cooling structures. Various TTFF structures are also possible. The TTFF may have a single-cavity Fabry-Perot structure or may have a multi-cavity structure. Packaging variants can also be made. Any one or more of several calibration aids can be included, such as an external source of one or more known wavelength signals, or an internal source of one or more known wavelength signals.

Abstract: Materials suitable for fabricating optical monitors include amorphous, polycrystalline and microcrystalline materials. Semitransparent photodetector materials may be based on silicon or silicon and germanium alloys. Conductors for connecting to and contacting the photodetector may be made from various transparent oxides, including zinc oxide, tin oxide and indium tin oxide. Optical monitor structures based on PIN diodes take advantage of the materials disclosed. Various contact, lineout, substrate and interconnect structures optimize the monitors for integration with various light sources, including vertical cavity surface emitting laser (VCSEL) arrays. Complete integrated structures include a light source, optical monitor and either a package or waveguide into which light is directed.

Abstract: Materials suitable for fabricating optical monitors include amorphous, polycrystalline and microcrystalline materials. Semitransparent photodetector materials may be based on silicon or silicon and germanium alloys. Conductors for connecting to and contacting the photodetector may be made from various transparent oxides, including zinc oxide, tin oxide and indium tin oxide. Optical monitor structures based on PIN diodes take advantage of the materials disclosed. Various contact, lineout, substrate and interconnect structures optimize the monitors for integration with various light sources, including vertical cavity surface emitting laser (VCSEL) arrays. Complete integrated structures include a light source, optical monitor and either a package or waveguide into which light is directed.

Abstract: A method of controlling an optical signal having a first wavelength, includes passing the optical signal through a device, the device substantially transparent to the first wavelength; and selectively illuminating the device with an optical signal at a second wavelength, illumination of the device by the second wavelength causing alteration of optical properties of the device relative to the first wavelength. An optically controlled optical filter, includes a semiconductor film whose transmission of a first optical wavelength varies with illumination at a second optical wavelength.

Abstract: An optical system including a steered beam, further includes a source of a light beam; a device which receives the light beam and steers it to form the steered beam; a target of the steered beam; and a semi-transparent sensor having an output signal indicative of a deviation of the steered beam from the target. A method of performing real-time control of an optical switch includes steering an optical beam onto a target within the switch; measuring a deviation of the optical beam from a nominal center of the target, while the optical beam is on the target; and correcting the direction of the optical beam to the nominal center of the target.

Abstract: The invention is directed to a method and an arrangement for the response analysis of semiconductor materials with optical excitation. The object of the invention, to find a new type of response analysis of semiconductor materials with optical excitation which also allows a sufficiently precise detection of the charge carrier wave with a higher excitation output and a shorter charge carrier lifetime, is met according to the invention in that an exciting laser beam is intensity-modulated with two discrete modulation frequencies (.OMEGA..sub.1 ; .OMEGA..sub.2), the luminescent light exiting from the object is measured on the difference frequency (.OMEGA..sub.1 -.OMEGA..sub.2), and the luminescent light is analyzed as a function of the arithmetic mean (.OMEGA.) of the modulation frequencies (.OMEGA..sub.1 ; .OMEGA..sub.2). The invention is applied in the semiconductor industry for determining different electrical parameters of semiconductor materials.

Abstract: A mass spectrographic method and apparatus provide simultaneous quantification of multiple target species of gaseous neutral particles that may be laser sputtered from a sample. The invention employs non-resonant multiphoton ionization of the target species with a high intensity laser beam propagated toward a given extraction volume from which volume ions are withdrawn for quantification. In preferred embodiments, the given volume is defined by an acceptance aperture and a transverse energy acceptance interval which is itself defined by energy discrimination of the ions into bunches with a novel ion mirror. An inventive embodiment of ion mirror has four grids at different spacings and potentials with a second grid away from the acceptance aperture having a potential just below a third to separate out an undesired, low-energy ion bunch. Curves for simultaneously quantifying Ta.sup.+ ions with Ta.sup.++ ions are shown.

Abstract: A process and arrangements for photothermal spectroscopy (thermal wave analysis) by the single-beam method with double modulation technique. A single-beam method is developed making use of the advantages of double modulation technique in detecting the photothermally generated difference frequency without requiring partial beams and while achieving extensive absence of intermodulation, the intensity of the laser beam is modulated before striking the object in such a way that the modulation spectrum substantially contains a carrier frequency (f.sub.1) and two sideband frequencies (f.sub.1 .+-.F.sub.2), wherein f.sub.2 is the base clock frequency of the modulation, a regulating detector and a control loop intervening in the modulation process suppress that component of the base clock frequency (f.sub.2) in the same phase with the mixed frequency of the carrier frequency and sideband frequencies.

Abstract: A method and apparatus for thermowave analysis employs a single laser beam, which has an additive, two-frequency, intensity modulation, and is directed onto the object. The amplitude of the mixed frequency of the discrete modulation frequencies, which is not contained in the exciting beam, is analyzed as response signal. By obtaining a reference signal from the exciting beam and forming the difference between this exciting beam and the measurement signal, noise suppression and a lowering of the limit of sensitivity are achieved in an advantageous manner.