Abstract: Provided are methods and systems for identification and analysis of materials and molecular structures. An apparatus for identification and analysis of materials and molecular structures may include a laser. The laser may, in turn, include an amplified spontaneous emission-suppressed single-frequency laser excitation source. The apparatus may further comprise a plurality of filters. The plurality of filters may include reflective volume holographic grating blocking filters. The apparatus may also comprise an optical unit and an optical spectrometer. The optical unit may be configured to deliver excitation energy to a sample substance and capture Raman signal scattering from the sample substance. The optical spectrometer may be disposed in a path of the Raman signal and configured to measure a spectrum of the Raman signal and generate a detection signal. Finally, the apparatus may comprise a processing unit configured to analyze the spectrum.

Abstract: Provided are methods and systems for identification and analysis of materials and molecular structures. An apparatus for identification and analysis of materials and molecular structures may include a laser. The laser may, in turn, include an amplified spontaneous emission-suppressed single-frequency laser excitation source. The apparatus may further comprise a plurality of filters. The plurality of filters may include reflective volume holographic grating blocking filters. The apparatus may also comprise an optical unit and an optical spectrometer. The optical unit may be configured to deliver excitation energy to a sample substance and capture Raman signal scattering from the sample substance. The optical spectrometer may be disposed in a path of the Raman signal and configured to measure a spectrum of the Raman signal and generate a detection signal. Finally, the apparatus may comprise a processing unit configured to analyze the spectrum.

Abstract: Systems and methods are provided herein. An exemplary system may include a laser source, the laser source having a laser center wavelength; at least one narrowband optical element receiving light emitted by the laser, the narrowband optical element having a filter center wavelength, the narrowband optical element being arranged such that the filter center wavelength is initially spectrally aligned with the laser center wavelength, the filter center wavelength changing in response to a temperature change such that the filter center wavelength is not substantially aligned with the laser center wavelength; and a passive adjustment mechanism coupled to the narrowband optical element, the passive adjustment mechanism including an actuator, the actuator moving in response to the temperature change, the actuator motion rotating the narrowband optical element, the rotation compensating for the temperature change such that the filter center wavelength and laser center wavelength remain spectrally aligned.

Abstract: The invention disclosed here teaches methods and apparatus for altering the temporal and spatial shape of an optical pulse. The methods correct for the spatial beam deformation caused by the intrinsic DC index gradient in a volume holographic chirped reflective grating (VHCRG). The first set of methods involves a mechanical mean of pre-deforming the VHCRG so that the combination of the deflection caused by the DC index gradient is compensated by the mechanical deformation of the VHCRG. The second set of methods involves compensating the angular deflection caused by the DC index gradient by retracing the diffracted beam back onto itself and by re-diffracting from the same VHCRG. Apparatus for temporally stretching, amplifying and temporally compressing light pulses are disclosed that rely on the methods above.

Abstract: The invention disclosed here teaches methods and apparatus for altering the temporal and spatial shape of an optical pulse. The methods correct for the spatial beam deformation caused by the intrinsic DC index gradient in a volume holographic chirped reflective grating (VHCRG). The first set of methods involves a mechanical mean of pre-deforming the VHCRG so that the combination of the deflection caused by the DC index gradient is compensated by the mechanical deformation of the VHCRG. The second set of methods involves compensating the angular deflection caused by the DC index gradient by retracing the diffracted beam back onto itself and by re-diffracting from the same VHCRG. Apparatus for temporally stretching, amplifying and temporally compressing light pulses are disclosed that rely on the methods above.

Abstract: The invention disclosed here teaches methods and apparatus for altering the temporal and spatial shape of an optical pulse. The methods correct for the spatial beam deformation caused by the intrinsic DC index gradient in a volume holographic chirped reflective grating (VHCRG). The first set of methods involves a mechanical mean of pre-deforming the VHCRG so that the combination of the deflection caused by the DC index gradient is compensated by the mechanical deformation of the VHCRG. The second set of methods involves compensating the angular deflection caused by the DC index gradient by retracing the diffracted beam back onto itself and by re-diffracting from the same VHCRG. Apparatus for temporally stretching, amplifying and temporally compressing light pulses are disclosed that rely on the methods above.

Abstract: The invention disclosed here teaches methods to fabricate and utilize a non-dispersive holographic wavelength blocker. The invention enables the observation of the Raman signal near the excitation wavelength (˜9 cm?1) with the compactness of standard thin film/holographic notch filter. The novelty is contacting several individual volume holographic blocking notch filter (VHBF) to form one high optical density blocking filter without creating spurious multiple diffractions that degrade the filter performance. Such ultra-narrow-band VHBF can be used in existing compact Raman instruments and thus will help bring high-end research to a greater number of users at a lower cost.

Abstract: The present invention relates to methods of measuring the optical characteristics of volume holographic gratings with high resolution and with a large spectral coverage using a spectrally broad band source in conjunction with instruments that measure the spectrum such as spectrometers, imaging spectrometers, and spectrum analyzers.

Abstract: The present invention relates to methods of measuring the optical characteristics of volume holographic gratings with high resolution and with a large spectral coverage using a spectrally broad band source in conjunction with instruments that measure the spectrum such as spectrometers, imaging spectrometers, and spectrum analyzers.

Abstract: The invention disclosed here teaches methods and apparatus for altering the temporal and spatial shape of an optical pulse. The methods correct for the spatial beam deformation caused by the intrinsic DC index gradient in a volume holographic chirped reflective grating (VHCRG). The first set of methods involves a mechanical mean of pre-deforming the VHCRG so that the combination of the deflection caused by the DC index gradient is compensated by the mechanical deformation of the VHCRG. The second set of methods involves compensating the angular deflection caused by the DC index gradient by retracing the diffracted beam back onto itself and by re-diffracting from the same VHCRG. Apparatus for temporally stretching, amplifying and temporally compressing light pulses are disclosed that rely on the methods above.

Abstract: The present invention relates to methods of measuring the optical characteristics of volume holographic gratings with high resolution and with a large spectral coverage using a spectrally broad band source in conjunction with instruments that measure the spectrum such as spectrometers, imaging spectrometers, and spectrum analyzers.

Abstract: The invention disclosed here teaches methods to fabricate and utilize a non-dispersive holographic wavelength blocker. The invention enables the observation of the Raman signal near the excitation wavelength (˜9 cm?1) with the compactness of standard thin film/holographic notch filter. The novelty is contacting several individual volume holographic blocking notch filter (VHBF) to form one high optical density blocking filter without creating spurious multiple diffractions that degrade the filter performance. Such ultra-narrow-band VHBF can be used in existing compact Raman instruments and thus will help bring high-end research to a greater number of users at a lower cost.

Abstract: The disclosed invention is an external cavity laser with a volume holographic VHG output coupler. The facet of the VHG is coated with a very high reflectivity coating (HR close to 100%) for the purpose of reflecting the second harmonic (SH) light generated intra-cavity. The HR coating for the SH light has also an anti-reflection (AR) coating at the fundamental wavelength. The reflected second harmonic (SH) light is either reflected directly out of the cavity by the VHG or back to the cavity towards the optics that deflect the SH light out of the cavity.

Abstract: A method is presented for shaping the spectral response of volume holographic grating elements by applying controlled thermal energy. The methods allow generating continuous or discontinuous grating periods from a fixed grating period. The methods are applicable to optical feedback into optical sources such as light emitting diodes, lasers and other general optical filtering applications.

Abstract: In the present invention, a volume holographic optical element is used as a pump coupler. The holographic coupler allows at least one pump wavelength to be coupled into the laser medium. The direction of the pump beam onto the coupler is not co-linear with the direction of the signal beam out of the coupler. The invention further provides the coupling of more than one pump wavelengths using a single holographic coupler element while maintaining the high isolation between pump and signal beam. The invention further provides a narrow-band reflection grating of various efficiencies for the signal beam (as part of the laser cavity).

Abstract: The present invention provides a multi-channel tunable filter and methods for making such a filter. In one embodiment, the filter comprises a bank of gratings or a continuously varying filter frequency imprinted into a filter material, such as Lithium Niobate or glass or polymer. An optical read-head comprising a pair of lenses is configured to pass light from within an optical fiber carrying multiple wavelengths through an appropriate grating to extract or drop a specific wavelength. To ensure continuous data transmission, the filter is tuned to a wavelength by configuring the read-head to move in a hitless manner. In one embodiment, the gratings are recorded by the interference of two beams. A first plane wave reflects off a first mirror stack and a second plane wave reflects off a second mirror stack. In another embodiment, the gratings are recorded by a phase masking method.

Abstract: The invention describes a system for the measurement of volume holograms on a wafer scale that permits high-resolution and high throughput measurement of grating parameters. The invention uses a collimated beam of a fixed wavelength light source that is transmitted through the wafer to be tested. The transmitted beam is imaged with a lens onto a sensor. The sensor is used to measure the beam power under a variety of conditions, including without a wafer in place, so that the various measurements can be used to determine grating characteristics. The measurement data produced includes values for grating spacing, tilt angle, and diffraction efficiency with a high spatial resolution.

Abstract: A tunable optical filter includes a movable reflector, such as a three-dimensional microelectromechanical system (MEMS) actuated mirror and a plurality of holographic gratings each having a predetermined Bragg wavelength to select the wavelength to be filtered or dropped from broadband or wavelength-multiplexed input optical signals.