Abstract:
A disc serving as a spatial radiation modulator has dispersed radiation filters thereon. Each filter has a transmittance or reflectance modulation function of the form sin2(mnullnullpnull/4), where m is a positive integer and p has one of the four values 0, 1, 2, 3. A radiation beam including selected wavelength components is diffracted into an elongated image dispersed according to wavelength. Different wavelength components are focused onto different filters on the modulator and are encoded by correspond filters. Since the modulation functions of the filters are orthogonal to one another, it is possible to extract the amplitude of each wavelength component after it has been encoded or modulated by corresponding filter from the total detected signal during one measurement.
Abstract:
For the colorimetric measurement of a two-dimensional original, the original is photoelectrically scanned pixel by pixel in a first step by way of a color-enabled photoelectric scanning device. A digital color representation of the original is produced from the thereby obtained scanning data. In a second step, suitable measuring positions are determined from the digital color representation of the original by way of a computer using image processing methods. In a third step, the color measuring head is automatically moved under the control of the computer to the so determined measuring positions and the original is colorimetrically measured at those measuring positions. The color data obtained thereby can be further processed, for example for the generation of apparatus profiles for the colorimetric control of output apparatus. The scanning device is preferably a high resolution flatbed or autofeed scanner or a digital camera. The color measuring head is preferably a spectral measuring head. By the comparatively high resolution pixel by pixel scanning of the original, the measuring positions can be very exactly determined without manual input and without time consuming multiple measurements. Furthermore, artifacts caused by dirt can be recognized and corrected.
Abstract:
A coupling mechanism for mounting a sample accessory assembly into a spectrometer. The accessory assembly, on which is mountable a sample to be analyzed by a spectrometer, has connecter ends which are insertable into stirrups on the sample compartment of the spectrometer. The connector ends and the stirrups have elements that ensure that the accessory assembly is properly aligned in the sample compartment of the spectrometer. The accessory assembly also has an electronic component, such as a circuit or programmable microchip, that is connected to the spectrometer when the accessory is mounted in the spectrometer. The electronic component provides information to the spectrometer identifying the accessory assembly being used so that a diagnostic test of the spectrometer can be performed to ascertain, for example, proper mounting of the accessory assembly in the spectrometer.
Abstract:
A handheld device for infrared reflectance measurements of samples for identification of the sample materials is a self-contained portable unit built into a handheld housing. The housing includes a window and optics on a bench adjacent the window, so that the optics will be aligned with the sample when the device is placed directly against the sample. The optics include a broad-band IR light source (ordinary lamp) shining onto an acousto-optic tunable filter (AOTF), which passes narrow-band IR light with a swept frequency; a lens focussing the IR through the window onto the sample; and a reflectance detector aligned with the window of the housing to pick up reflected light. A computer, which may be mounted in the housing, compares the detected reflectance spectrum with stored sample data spectra, and identifies the material or the components of the material and their proportions. Inclusion of all the parts inside the housing allows the device to be portable; this is made possible by the alignment of the lamp, AOTF filter, lens, window, and detector, which has high optical efficiency, and by elimination of optical fibers.
Abstract:
A mechanism for aligning the elements of an optical system is disclosed. One aspect of the present invention is an alignment mechanism which includes lead screws placed on opposite corners of the elements to be aligned. The elements are provided with threaded holes of different pitch, and the lead screw is provided with threads of the same unequal pitches as the elements, thereby forming a differential lead screw. The threads include a locking thread which assures a positive lock between the lead screw and the elements to be aligned and eliminates backlash between them. Another aspect of the present invention is an interference fit mechanism which is provided by the employment of a slightly-oversized flexible boss which mates with a cavity. The boss is provided with a thin outer wall capable of flexing when the boss is inserted into the cavity. Yet another aspect of the present invention includes a wobble plate comprising a spherical socket and housing. The housing includes a mounting for an optical element and is rotatable within the socket. Application of an adhesive to the space between the socket and housing secures the relative positions of the socket and housing when the alignment operations have been completed.
Abstract:
Disclosed is a dispersive optics system, in the context of sample substrate system investigating spectroscopic reflectometer and the like systems, which, in use, produce a plurality of "Orders" of essentially single wavelength beams of light from a polychromatic beam of light. In use the availability of more than one "Order" of essentially single wavelength beams of light allows simultaneous measurement of more essentially single wavelength beams of light, over a larger range, than would be possible were only one "Order" of essentially single wavelength beams of light present. Filters are present to reduce the effects of stray light on detector elements and to allow separating the wavelengths in overlapping regions of adjacent Orders. Also disclosed is a quadrant detector means of dispersive optics alignment, and a compensator means for reducing the effect of detector element polarization state dependence.
Abstract:
Disclosed is a dispersive optics system, in the context of ellipsometer or polarimeter and the like systems, which, in use, produces a plurality of "Orders" of essentially single wavelength beams of light from a polychromatic beam of light. In use the availability of more than one "Order" of essentially single wavelength beams of light allows simultaneous measurement of more essentially single wavelength beams of light than would be possible were only one "Order" of essentially single wavelength beams of light present. Filters are present to reduce the effects of stray light on detector elements and to allow separating the wavelengths in overlapping regions of adjacent Orders.
Abstract:
A spectrophotometer is described, comprising a single light source, a single detector, optics for dually and alternatively reading a sample and a reference, and only one moving part. That moving part is a chopper containing multiple pass-through apertures, each filled with a unique bandpass filter to select wavelengths to specifically illuminate the sample or reference. To inform the spectrophotometer whether and when it is reading the sample or the reference, trigger means are provided in at least twice the number of the pass-through apertures.
Abstract:
An infrared microscope spectrometer is used to carry out attenuated total reflection (ATR) analysis of a sample. Either the collecting element assembly or focusing element assembly is mounted for selected movement with respect to the other so as to permit alignment of the output beam from the focusing assembly with the optical axis of the spectrometer, whenever an ATR crystal with sample is placed between the collecting and focusing assemblies.
Abstract:
Apparatus for inserting and removing several filters from an optical path and for determining at all times the instantaneous positional relationship of each filter with respect to the optical path includes a set of filters mounted on a carrier which is attached to a resonant piezoelectric system, and further includes reference tracks also located on the carrier and extending in the direction of the oscillatory motion and including a sequence of binary indicia progressing in the direction of the oscillatory motion. The reference tracks are read optically to produce a series of binary electrical signals which are processed to yield the instantaneous position of the carrier and filters with respect to a fixed optical path.