116 results about "Spectral dispersion" patented technology

A control system and apparatus for use with an ultra-fast laser is provided. In another aspect of the present invention, the apparatus includes a laser, pulse shaper, detection device and control system. A multiphoton intrapulse interference method is used to characterize the spectral phase of laser pulses and to compensate for any distortions in an additional aspect of the present invention. In another aspect of the present invention, a system employs multiphoton intrapulse interference phase scan. Furthermore, another aspect of the present invention locates a pulse shaper and/or MIIPS unit between a spectral dispersion point in a laser oscillator and an output of a laser amplifier.

The present invention provides a slit-scan multi-wavelength confocal lens module, which utilizes at least two lenses having chromatic aberration for splitting a broadband light into continuously linear spectral lights having different focal length respectively. The present invention utilizes the confocal lens module employing slit-scan confocal principle and chromatic dispersion techniques and the confocal microscopy with optical sectioning ability and high resolution in spectral dispersion to establish a confocal microscopy method and system with long DOF and high resolution, capable of modulating a broadband light to produce the axial chromatic dispersion and focus on different depths toward an object's surface for obtaining the reflected light spectrum from the surface. Thereafter, the spectrum is spatially filtered by a slit and then a peak position with respect to the filtered spectrum along the scanning line is detected by a spectral image sensing unit for generating the sectional profile of the measured surface.

We describe a variable bandwidth tunable optical spectral filtering device and associated method for selectively directing a portion of a wavelength multiplexed input signal, entering through one or more optical fibers, into one or more output signals provided to one or more optical fibers and/or electronic outputs. The optical filtering is accomplished using free-space diffractive wavelength de-multiplexing optics combined with a fixed (permanent) patterned structure located in the spectrally dispersed image plane. The structure can direct a selected spectral portion of the optical signal to one or more separate outputs, such as an optical fiber or power detector. A single active element in the optical path is used to spatially shift, or steer, the entire input spectrum at the dispersed spectral image plane, to control the portion of the input spectrum illuminating specific features on the permanent patterned structure. In one preferred embodiment, a device with a fixed selective area triangular shaped tilted reflective facet on a flat reflective surface is constructed such that the light reflected off the flat reflective surface and off the triangular reflective facet are selectively multiplexed back and directed to different output fiber ports. Inputs at different angles of incidence on the reflective structures may be deflected by the same structures to different output port fiber ports. A reconfigurable variable-bandwidth tunable optical add/drop multiplexing device is constructed using such a filtering device and an application of such an add/drop multiplexing in a optical transport network is demonstrated.

A spectral encoder for producing spectrally selected images of a radiation field containing multiple spectral components. An imaging spectrograph defines a first optical path that produces from the input radiation field a spectrally dispersed image comprising multiple spectral components displaced along a dispersion direction. Spectral pass bands are encoded on the dispersed image by a programmable spatial light modulator using one or more spatial masks. The imaging spectrograph further defines a second optical path that reverses the spectral dispersion of the first path and produces a spectrally-encoded polychromatic output image containing only those spectral components encoded by the spatial mask. The first and second optical paths share a common dispersing element. A detector records at least one spatial region of the spectrally encoded output image.

A method of tuning the time duration of laser output pulses, the method including spectrally dispersing optical pulses and further comprising providing an optical pulse having a time duration and a spectral bandwidth; spectrally dispersing (243, 245) the optical pulse so as to provide a selected change in the time duration of the pulse responsive to the spectral band-width of the pulse; outputting (226) an optical output pulse having a first time duration that is responsive to the selected change in time duration; providing another optical pulse; changing the amount of spectral bandwidth of the another optical pulse (272) to be different than that of the optical pulse or changing the amount of spectral dispersion so that spectrally dispersing the another optical pulse provides a change in time duration that is different than the selected change; and outputting (226) another optical output pulse having a second time duration that is responsive to the different change in time duration, the second time duration of the another optical output pulse being different than the first time duration of the optical output pulse.

The invention relates to a detection method and device of optical component surface topography and subsurface defect information. The method comprises the following steps that wavelength information is used to measure a distance, one beam of compound color light (white) with a broad spectrum is emitted by a light source, spectral dispersion is generated through a dispersive lens to form monochromatic light with different wavelengths, and a focal point of each wavelength corresponds to one distance value; measurement light is reflected back from a surface of an object, the monochromatic light satisfying a confocal condition can be sensed by a spectrometer through a small hole, and the acquired distance value is converted through calculating the wavelength of the sensed focal point; and thetwo spectrometers are used to receive a surface of a component to be tested and light wave information of an internal defect so as to obtain surface information of the optical component, a position ofthe internal defect, depth information and the like simultaneously.

The invention relates to an apparatus for optical spectroscopy having means to produce an interference pattern and having a spatially resolving detector which can record the interference pattern produced. In accordance with the invention, the wavefronts of at least one of the part rays involved in the interference pattern is influenced in dependence on the wavelength by spectrally dispersive or diffractive optical elements.

The present invention relates to a chirp pulse amplifying spectrum shaping dielectric film structure reflector, which comprises a transparent substrate, a high reflectance film system, an anaglyph structure and an external protective layer. Wherein, the high reflectance film system is composed of a plurality of staggered dielectric films. A high reflectance film layer and a lower reflectance film layer of the high reflectance film closely contact the anaglyph structure. The anaglyph structure can take a plurality of shapes, such as a micro-lens high transparency film system structure, an air dielectric structure, a glass anaglyph structure or other transparent dielectric structures, including semiconductor structures. As a high-power laser chirp pulse with a plane wave structure vertically casts onto the reflector, the laser passes through the high reflectance film system and the anaglyph structure and all residual lasers are reflected to back of the reflector through the transparent substrate. Reflex intensity distribution is modulated to a needed spectrum distribution structure. The reflector of the present invention can be inserted into any place of an amplifier link and improve capacity to distinguish shaping spectrum chromatic dispersion to a certain level. Scope modulation exceeds 60% without changing phase position, thus adapting to PW devices.

The present invention relates to a system and methods for acquiring two-dimensional Fourier transform (2D FT) spectra. Overlap of a collinear pulse pair and probe induce a molecular response which is collected by spectral dispersion of the signal modulated probe beam. Simultaneous collection of the molecular response, pulse timing and characteristics permit real time phasing and rapid acquisition of spectra. Full spectra are acquired as a function of pulse pair timings and numerically transformed to achieve the full frequency-frequency spectrum. This method demonstrates the ability to acquire information on molecular dynamics, couplings and structure in a simple apparatus. Multi-dimensional methods can be used for diagnostic and analytical measurements in the biological, biomedical, and chemical fields.

The invention discloses a super lateral resolution surface three-dimensional online interference measuring system based on a spectral dispersion full field, and belongs to the field of optical measurement. The system is composed of a broadband light source, an isolator, a fiber, a fiber joint, a spherical-surface and cylindrical-surface spectroscopes, spectroscopes, right-angle prisms, diaphragms, a raster, a reflector, a surface array detector, a photoelectric detector, a Fabry-Perot filter, piezoelectric ceramics, a signal processing circuit, a feedback control circuit, a data acquisition card, a computer, translation benches, a translation bench driving part, a result output part and the like. The raster disperses a broadband spectrum to form a mating plate whose wavelength is continuously distributed in a transverse direction, and the mating plat is incident vertically to a measured surface through beam expansion for full-field measurement; a surface provided with a step whose height difference is greater than a half-wavelength and a large-depth-to-width-ratio groove is measured by use of two wavelengths; super lateral resolution measurement is realized by use of the Fabry-Perot filter; and ambient interference is compensated through feedback control, the system is enabled to be suitable for online measurement, the measuring result can be accurately traced to a wavelength reference, and the influence of the drift of a light source spectrum is eliminated.

The present invention relates to a spectrally dispersive interferometric optical apparatus having a light source, generating a phase shift, measuring the intensity of the interference signals, selectively measuring the intensity of the interference signal and determining the phase angles and/or a relative phase shift of the intensity of the interference signals. In accordance with the invention, the generating of a phase shift between components of different polarization directions in at least one of the branches of the interferometer includes a diffraction grating. The selective determination of the intensity of the interference signal in dependence on the polarization moreover permits determination of the respective intensity for the TE components and for the TM components of the interference signal with respect to the coordinate system of the diffraction grating.

The invention provides an unmanned area target detection method. The unmanned area target detection method comprises the following steps: carrying out AD sampling on echo signals, wherein the echo signals are reflection signals of detection wave signals sent by a detection radar after the detection wave signals reach targets; carrying out range-direction Fourier transform on the sampled signals to obtain a single repetition-frequency one-dimensional range image; carrying out MTI filtering on a plurality of repetition-frequency one-dimensional range images; carrying out non-phase-coherent accumulation on filtered data to obtain non-phase-coherent accumulation results of the echo signals; and carrying out constant false-alarm rate detection on the non-phase-coherent accumulation results of the echo signals and judging whether the targets exist in a detected area. The unmanned area target detection method adopts a dual-delay-line canceller, so that the inhibition capability on zero-frequency clutters can be effectively improved; through the adoption of the azimuth-direction non- phase-coherent accumulation, the azimuth-direction spectral dispersion effect is effectively avoided; in addition, the zero-frequency resolution ratio and the signal-to-clutter ratio of an azimuth Doppler can be further improved by increasing MTI filtering points and non-phase-coherent accumulation points.

The invention provides a novel hadamard transform near-infrared spectrometer, which aims to improve the luminous flux of single micromirrors of a micromirror array of the hadamard transform near-infrared spectrometer further to improve detection sensitivity and signal-to-noise ratio. The hadamard transform near-infrared spectrometer comprises an one-dimensional micromirror array arranged by the micromirrors; the shapes of mirror faces of the micromirrors are strips with long axes and short axes; the one-dimensional micromirror array is formed by the micromirrors which are parallelly and linearly arranged along the short axis direction of the mirror faces of the micromirrors; and the arrangement direction is along a spectral dispersion direction. Lights in different wavelength intervals which are subjected to chromatic dispersion through a preposition optical system and a grating are irradiated to the surfaces of the micromirrors respectively which are parallelly arranged, and are focused on a detector by a postposition optical system through the reflection of the micromirrors. The areas of the single micromirrors are increased, and the luminous flux is increased, so the adoption of the technical proposal can ensure that the detection sensitivity of an instrument is improved, and the signal-to-noise ratio of a detection result is improved by more than 10 times.

Disclosed is a spectrally encoded coherent anti-Stokes Raman scattering (CARS) endoscope that is capable of spatially encoding spectral dispersions of two light sources having frequency difference as much as a Raman shift and overlapping two laser beams on a position where a sample to be measured is placed, thereby acquiring a spatial distribution of CARS signals.