Abstract:
A non-relayed reflective triplet and a double-pass imaging spectrometer including the reflective triplet configured as its objective. In one example the reflective triplet includes a primary mirror that receives and reflects electromagnetic radiation from a viewed scene and defines an optical axis of the optical system, a secondary mirror that receives and reflects the electromagnetic radiation reflected from the primary mirror, and a tertiary mirror that receives the electromagnetic radiation reflected from the secondary mirror and focuses the electromagnetic radiation onto an image plane to form an image of the viewed scene. The primary, secondary, and tertiary mirrors together are configured to form a virtual exit pupil for the optical system, the image plane being located between the tertiary mirror and the virtual exit pupil. The reflective triplet is on-axis in aperture and off-axis in field of view.
Abstract:
A light source for near-infrared transmission and reflection spectroscopy can be constructed from a combination of a high power blue or blue-green light emitting diode (LED) and a phosphor element based on an inorganic material. The phosphor element absorbs the LED light and, in response to the LED excitation, emits luminescence that continuously covers the 700 – 1050 nm range. One possible material that can be used for such a near-infrared emitting phosphor element is a single crystal rod of Ti+3 doped Sapphire. An alternative near-infrared emitting phosphor material is a disk or rectangular shaped composite of Ti+3 doped Sapphire powder embedded in a clear optical epoxy or silicone encapsulant. Such a combination of a blue LED for excitation of a phosphor element that emits in a broad wavelength band has been widely used in white LEDs where the emission is in the 400-700 nm range.
Abstract:
A light source for near-infrared transmission and reflection spectroscopy can be constructed from a combination of a high power blue or blue-green light emitting diode (LED) and a phosphor element based on an inorganic material. The phosphor element absorbs the LED light and, in response to the LED excitation, emits luminescence that continuously covers the 700 – 1050 nm range. One possible material that can be used for such a near-infrared emitting phosphor element is a single crystal rod of Ti+3 doped Sapphire. An alternative near-infrared emitting phosphor material is a disk or rectangular shaped composite of Ti+3 doped Sapphire powder embedded in a clear optical epoxy or silicone encapsulant. Such a combination of a blue LED for excitation of a phosphor element that emits in a broad wavelength band has been widely used in white LEDs where the emission is in the 400-700 nm range.
Abstract:
In an embodiment, an apparatus includes a module assembly and a main assembly. The module assembly includes a module assembly housing, a first face plate and an analysis unit attached to the first face. The main assembly includes a main assembly housing, a second face plate and an engine unit rigidly attached to the second face plate. The engine unit generates a light that passes to the analysis unit via a first lens assembly and a second lens assembly. The first lens assembly is attached to the first face plate and the second lens assembly is attached to the second face plate. The module assembly when attached to the main assembly causes the first and second face plates to act as a single mechanical unit that moves independent of movement of the module assembly housing and/or the main assembly housing.
Abstract:
A method and apparatus for enhanced THz radiation coupling to molecules, includes the steps of depositing a test material near the discontinuity edges of a slotted member, and enhancing the THz radiation by transmitting THz radiation through the slots. The molecules of the test material are illuminated by the enhanced THz radiation that has been transmitted through the slots, thereby producing an increased coupling of EM radiation in the THz spectral range to said material. The molecules can be bio- molecules, explosive materials, or species of organisms. The slotted member can be a semiconductor film, a metallic film, in particular InSb, or layers thereof. THz detectors sense near field THz radiation that has been transmitted through said slots and the test material.
Abstract:
In a spectrometer, preferably in a spectrometric microscope, light from a specimen is collected at a collector objective element and delivered to a camera element, which in turn provides the light to a photosensitive detector. A focal plane is provided between the collector objective element and the camera element, and one or more aperture arrays may be situated in the focal plane to restrict the detector's field of view of the specimen to the areas within the apertures. By utilizing aperture arrays with apertures of different sizes and shapes, the spatial resolution of the spectrometer readings may be varied without the need to vary the optics of the spectrometer. As a result, if the optics are optimized to minimize vignetting, spatial resolution may be varied without adverse increases in vignetting.
Abstract:
In a spectrometer, preferably in a spectrometric microscope, input light is provided from a light source to a specimen via a source objective element (e.g., a Schwarzchild objective), and the aperture of the light source is matched to the aperture of the source objective element to maximize light throughput to the specimen. The light from the specimen is then collected at a collector objective element and delivered to a camera element, which in turn provides the light to a photosensitive detector. The apertures of the camera element and the collector objective element are also matched to maximize light throughput from the specimen to the detector. As a result, light loss from vignetting effects is reduced, improving the intensity and uniformity of illumination and the sensitivity and accuracy of spectral measurements.
Abstract:
The disclosure relates generally to methods and apparatus for using a fiber array spectral translator-based ("FAST") spectroscopic system for performing spectral unmixing of a mixture containing multiple polymorphs. In an embodiment, a first spectrum of a mixture containing polymorphs of a compound is obtained using a photon detector and a fiber array spectral translator having plural fibers. A set of second spectra is provided where each spectrum of the set of second spectra may be representative of a different polymorph of the compound. The first spectrum and the set of second spectra may be compared, and based on the comparison, the presence of one or more polymorphs in the mixture may be determined.
Abstract:
A spectrophotometer has a first photodetector (24) and a second photodetector (25) which is displaced spatially from the first photodetector in the direction of increasing wavelength in the spectrum. At any given time the second photodetector receives light at a wavelength which is substantially greater than that being received simultaneously by the first photodetector at that time. The first photodetector has a first range of wavelengths over which it is operable and a first upper operating limit, and the second photodetector has a second range of wavelengths over which it is operable and a second upper operating limit, the second range overlapping the first range and the second upper operating limit being greater than the first upper operating limit. Thus the range of operation is extended, and data in two different ranges is processed simultaneously. The spectrophotometer comprises a housing (1) containing a light source (11), a monochromator (15, 16, 18) and the photodetectors, there being a fibre optic connected to a probe (2) for transmitting light from the light source to a sample to be analysed and receiving light from the sample. Optical components are mounted to a chassis (26) of the housing rigidly, the chassis being connected to the housing by shock absorbing mounts (28, 29). The light source is mounted to the housing by means of an adjuster (24) providing for adjustment laterally with respect to the optical axis of the light source.
Abstract:
In one embodiment, the disclosure relates to a method including: collecting photons from the sample having a plurality of regions to form a sample optical data set; selectively transmitting a first portion of the optical data set through a first of a plurality of apertures of an electro-optical shutter, each of the plurality of apertures optically communicating a portion of the optical data set; geometrically conforming the first portion of the optical data set for communication with a spectrometer opening; processing the conformed first portion of the optical data set at the spectrometer to obtain a spectrum for a first of the plurality of sample regions.