Abstract:
A transmissive diffraction grating includes a polarization conversion layer, a first diffractive layer disposed on one surface side of the polarization conversion layer, and a second diffractive layer disposed on the other surface side of the polarization conversion layer. Both the first diffractive layer and the second diffractive layer include refractive index modulation structures arranged with a period P in a first direction, and diffraction efficiency for a TE polarized light component is higher than a diffraction efficiency for a TM polarized light component.
Abstract:
The present invention includes a slanted periodically poled device 12 including a light input surface 12a and a light output surface 12b parallel to each other and a terahertz wave input surface 12c orthogonal to the light input surface 12a and the light output surface 12b, a pump beam source 14 which emits pump beam 1 perpendicularly to the light input surface 12a, and a photodetector 16 which detects an up-conversion signal beam A converted from a terahertz wave 3 emitted perpendicularly from the light output surface 12b. The slanted periodically poled device 12 is configured to generate the up-conversion signal beam A in the same direction as and in parallel with the pump beam 1 by quasi phase matching between the terahertz wave 3 perpendicularly incident from the terahertz wave input surface 12c and the pump beam 1.
Abstract:
Snapshot spectral imagers comprise an imaging lens, a dispersed image sensor and a restricted isometry property (RIP) diffuser inserted in the optical path between the source image and the image sensor. The imagers are used to obtain a plurality of spectral images of the source object in different spectral bands in a single shot. In some embodiments, the RIP diffuser is one dimensional. An optional disperser may be added in the optical path, to provide further dispersion at the image sensor. In some embodiments, all imager components except the RIP diffuser may be part of a digital camera, with the RIP diffuser added externally. In some embodiments, the RIP diffuser may be included internally in a digital camera.
Abstract:
A dispersion spectrometer comprises a wavelength dispersive element located within a path of incoming radiant energy; and a first detector disposed to detect incoming radiant energy dispersed by the dispersive element, The spectrometer further comprises a second detector disposed to register the intensity of at least a portion of the un-dispersed incoming radiation and configured to generate a signal representative of the registered intensity, the first detector being adapted to have operational parameters in the form of integration time and/or sensitivity gain varied in response to the signal.
Abstract:
A system or method for analyzing a sample include an input light source, an excitation light source positioned to receive light from the input light source and to sequentially illuminate the sample with each of a plurality of wavelengths, a fluorescence detector positioned to receive and substantially simultaneously detect multiple wavelengths of light emitted by the sample for each of the plurality of excitation wavelengths, an absorption detector positioned to receive and detect light passing through the sample, and a computer in communication with the excitation light source, the fluorescence detector, and the absorption detector, the computer controlling the excitation light source to sequentially illuminate the sample with each of the plurality of wavelengths while measuring absorption and fluorescence of the sample based on signals received from the fluorescence and absorption detectors.
Abstract:
Provided is a method for performing a wavelength calibration of a monochromator with a diffraction grating by casting light from a standard light source whose emission intensity contains a change with a predetermined cycle onto the diffraction grating and measuring an intensity of light reflected by the grating. The method includes the steps of: measuring at least two times the intensity of the reflected light from the grating within the aforementioned cycle at each of the rotational positions of the grating corresponding to a range of wavelengths including a peak wavelength of a bright line spectral light generated by the standard light source; determining an intensity value 201 at each rotational position based on all the measured values obtained at the rotational position; and locating, as the peak wavelength of the bright line spectral light, a wavelength at which the intensity value 201 is maximized.
Abstract:
A measurement apparatus includes a first light source unit configured to emit a first light having a first wavelength, and a scanning unit configured to move an irradiation position of the first light with respect to a specimen, so as to scan the specimen with the first light. The first light source unit includes a wavelength changing unit configured to change the first wavelength. Movement of the irradiation position is performed by the scanning unit while the wavelength changing unit is changing the first wavelength. A changing cycle of the first wavelength by the wavelength changing unit is shorter than a position moving cycle by the scanning unit.
Abstract:
A fluorescence spectrophotometer according to the present invention includes: a light source 1; a sample cell 3; an excitation-side light-dispersing system 2 for dispersing a light from the light source 1 and for casting a desired wavelength of light into the sample cell 3; an emission-side light-dispersing system 4 for dispersing a light emitted from the sample cell 3, the emission-side light-dispersing system 4 being located off an optical path of a transmitted light exiting from the sample cell 3 after being cast from the excitation-side light-dispersing system 2 into the sample cell 3; and a photodetector 5 capable of detecting, among the light from the emission-side light-dispersing system 4, an emission light having the same wavelength as the light cast from the excitation-side light-dispersing system 2 into the sample cell 3.
Abstract:
A portable hyperspectral imager. The imager is modular and may include a hyperspectral camera and a removably-coupled mobile display module. The hyperspectral camera may include an Offner spectrometer. The mobile display module may be adapted to receive data from the hyperspectral camera and may include an internal camera. The mobile display module may include a cell phone or a tablet computer. The mobile display module may be integrally attached to the hyperspectral camera. The integral attachment may include a data link or USB connection. The length of the data link or USB connection may be less than 6 inches and the imager may weigh less than one pound. The imager may include a battery module or a scanning optical module.
Abstract:
The bandwidth selection mechanism includes a first actuator mounted on a second face of a dispersive optical element, the second face being opposite from a reflective face, the first actuator having a first end coupled to a first end block and a second end coupled to a second end block, the first actuator being operative to apply equal and opposite forces to the first end block and the second end block to bend the body of the dispersive optical element along the longitudinal axis of the body and in a first direction normal to the reflective face of the dispersive optical element. The bandwidth selection mechanism also includes a second actuator being operative to apply equal and opposite forces to bend the body along the longitudinal axis of the body, in a second direction perpendicular to the reflective face of the dispersive optical element.