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 microscope for use in transmissive and reflective infrared spectral analysis of a sample positioned on a sample plane. The microscope uses a collimated beam for infinity correction. A collimated irradiating beam of infrared energy is input to the microscope and focused through a single confocal aperture whereupon the beam is re-collimated and provided to a focusing lens. The focusing lens focuses the beam on a subject sample which generates a resulting image beam. The resulting image beam is re-collimated and provided to an optical element which focuses the resulting image beam back through the single confocal aperture and to an infrared detector. In a preferred embodiment, the size of the single confocal aperture is adjustable and a dichroic element is included for providing simultaneous viewing and infrared measurement of a measured sample. Also in a preferred embodiment, a detector mounting apparatus is included for facilitating orientation of a detector at an infrared output of the microscope.

Abstract: This invention is an apparatus and method for infrared spectroscopic or radiometric analysis of microscopic samples of solids or liquids, combining external- or internal-reflection spectroscopy with visible-radiant energy viewing of microscopic samples by integrated video microscopy. This is an accessory to Fourier-transform-infrared spectrometers for the chemical analysis of microscopic samples in specular, diffuse, reflection-absorption (transflection), or internal-reflection spectroscopy. This apparatus combines an all-reflective, infinity-corrected optical system with an integrated, dedicated, video viewing system. The magnification optic is an all-reflecting optic designed to focus a collimated beam of radiant energy onto the sample, collect the reflected radiant energy, and (through the appropriate optics) present that energy to a detector means for spectral analysis.

Abstract: An optical system, apparatus and method includes a visible energy source and a radiant energy source, means to direct visible or radiant energy at preselected but variable angles of incidence through an ATR crystal to a sample at a sample plane and means to collect encoded radiant energy reflected or emitted from the sample through the ATR crystal to a detector at preselected but variable angles of reflection or emission. The optical system, apparatus and method may further include a lens or other optical element selectively positioned in the optical path to change the focus of the optical path to initially survey the sample on a movable stage at a focal plane spaced from the sample plane. The survey mode permits easy identification of a surface area of interest on the sample to permit that area of interest to be moved into contact with a surface of the ATR crystal at the sample plane for subsequent accurate analysis thereof.

Abstract: An optical system, apparatus and method for analyzing samples includes a radiant energy source, a first mask, a first mirror system, a sample plane, a second mirror system, a second mask and a detector. The first and second masks are respectively positioned along the optical path of the system in the same or different Fourier planes and/or conjugate planes thereof. The first mask has at least one inlet aperture with the relative position thereof in the first mask determining the angle of the energy incidence onto the sample. The second mask has at least one outlet aperture therein passing radiant energy therethrough which has been reflected from or transmitted through the sample at a preselected angle determined by the relative position of the second aperture in the second mask.

Abstract: An optical system, apparatus and method for analyzing samples includes a radiant energy source, a first mask, a first mirror system, a sample plane, a second mirror system, a second mask and a detector. The first and second masks are respectively positioned along the optical path of the system in the same or different Fourier planes and/or conjugate planes thereof. The first mask has at least one inlet aperture with the relative position thereof in the first mask determining the angle of the energy incidence onto the sample. The second mask has at least one outlet aperture therein passing radiant energy therethrough which has been reflected from or transmitted through the sample at a preselected angle determined by the relative position of the second aperture in the second mask.

Abstract: A sampling probe for optical analyzation of a sample includes an MIR element having a cylindrical body with a flat end and a curved end. The flat end and the adjacent active portion of the body is positioned against the sample, and the curved end is operative to receive and emit radiant energy internally multiply reflected in both directions along the MIR element to optically analyze the sample. For high pressure and/or high temperature applications, the MIR element is preferably a crystal partially mounted in and sealed to a holder, which in turn is mounted in and sealed to one wall of a fluid or reaction chamber. The crystal or adjacent holder surface is coated or mirrored to enhance optical efficiency, and the crystal is secured within and sealed to the holder by soldering, an adhesive bond or a prestressed friction fit.

Abstract: An improved aperture beam splitter comprises an intercepting mirror positioned at an aperture image plane that is remote from any focus so as to deflect one half of the energy in a beam of incident radiant energy. the aperture image plane corresponds to an aperture stop and one half of an incident beam of radiant energy is lost at the aperture image plane. The remaining energy supplies the input to an optical system. The radiant energy from the output of the optical system reaches an image plane corresponding to the aperture image plane. Preferably, the optical paths of the incident and returning radiant energy are sufficiently coincident in space that the aperture image plane returns to the intercepting mirror. If the optical system forms the radiant energy into an odd number of foci, the image formed at the aperture image plane experiences a mirror symmetry reversal.

Abstract: A universal microscope for use with a commercial FT-IR spectrophotometer comprises a visible light microscope for selecting and masking an area of a sample and an infrared microscope for sampling the masked area. The visible light microscope and the infrared microscope share a common optical path between one or more remote sample image plane masks and the sample plane such that both the visible light and the infrared radiant energy are masked twice to spatially define the same area at the sample plane. The first sample image plane mask removes energy from outside the target area at the sample focus. The second sample image plane mask removes energy from outside the target area that is diffracted by the first mask or the focusing optics. The first remote sample image plane is imaged onto the second remote image plane with the radiant energy gaining spectroscopic information and additional image information by passing through or reflecting off a sample located at the intervening sample plane.

Abstract: A modified Schwarzschild Casegrainian objective reflects radiant energy between the primary and secondary mirror two times to form a four reflection optical path. The four reflection optical path increases the magnification of the objective without making the working distance that separates the secondary mirror from the sample unacceptably small. The four reflection optical path maintains good image quality at high numerical aperture due, at least in part, to the relatively small size of a microscopic object. The objective functions as a zoom lens by changing the location of a remote field stop along the optical axis of the objective and refocusing because the emerging beam of radiant energy is nearly collimated along the optical axis at the field stop. The reflecting objective also obtains variable magnification by converting to a two reflection mode of operation by increasing the separation of the primary mirror from the secondary mirror from the sample image plane.

Abstract: A spectroscopy system separates the diffuse reflectance component of a reflectance spectrum from the specular reflectance component using a remote field stop filter. The surface of the sample is placed at a focal plane of an optical system. The optical system forms an image on the surface of the sample that includes an image of the remote field stop filter. The optical system images the surface of the sample onto either the same or another remote field stop. Energy reflected from the surface of the sample which is in focus at the remote field stop retains the image information about the image of the filter, whereas energy reflected from below the surface of the sample does not necessarily retain image information about the image of the filter.

Abstract: A grazing angle microscope includes a highly convex central spherical mirror segment and a highly concave annular spherical mirror segment. A beam of incident radiant energy is sequentially directed against a part of the first convex mirror and a first part of the concave mirror onto a surface area at grazing angles so as to form a focused image on the surface area. A second part of the concave mirror collects radiant energy reflected from the surface at grazing angles and directs it to a second part of the convex mirror for reflection to a detector. Masking means are located at a focus that is remote from the surface area to determine the geometric shape of the image of the remote focus to target the surface area to be sampled by radiant energy. The masking means is adjusted during viewing in a visible light mode, with the visible light having a common optical path and common focal points with the radiant energy.

Abstract: A multiple internal reflectance crystal has a sample surface and a bottom surface and reflective beveled ends such that energy may enter normal to the bottom surface, reflect off one beveled end to the bottom surface, from the bottom surface to the top surface, down the length of the crystal, and exit the crystal normal to the bottom surface by reflecting off of another beveled end. The crystal may be optically linked with light pipes and positioned at a location remote from the source and receiver of energy.

Abstract: The optical system of the present invention comtemplates directing a beam of radiant energy to either an aperture beam splitter or polarizing beam splitter. Radiant energy from the beam splitter forms a first remote image at an entrance to an image scrambler so that any image information which the beam contains is destroyed. The output of the scrambler fills the full aperture of a focusing objective that reproduces the image of the output of the scrambler onto a sample. A mask, positioned at a remote image between the output of the scrambler and focusing objective, determines the geometrical shape of the sample image. The focusing objective images the radiant energy that is reflected from the sample to a second remote image at the scrambler so that the scrambler destroys image information while retaining spectroscopic information. The beam splitter reflects a portion of the radiant energy from the scrambler to the detector.

Abstract: Diffuse reflectance spectra may be obtained that are free from the distortions caused by specular reflections by using an apparatus and method for physically blocking out specularly reflected energy. The apparatus consists of a blocker that is positioned substantially in contact with the surface of the sample at the region wherein an input beam of energy is focused on the sample. Specularly reflected energy that would otherwise be reflected to a detector is physically blocked by the blocker. That part of the input energy beam that penetrates into the sample is diffusely reflected. Part of the diffusely reflected energy passes under the blocker where it is collected and focused on the detector. The blocker is found to have particular application in the field of infrared spectroscopy of inorganic compounds, particularly compounds having a powdered structure.

Abstract: A reflecting beam splitting objective employing only three mirrors obtains a high reflective efficiency. In one embodiment, the objective contains a small intercepting mirror between primary and secondary mirrors of a Cassegrain mirror arrangement. The position of the intercepting mirror is determined so that the mirror receives an input beam and directs that beam onto a first portion of the secondary mirror without vignetting the beam when it is reflected from the secondary mirror to a first portion of the primary mirror or by cutting off part of the image transmitted from the second portion of the secondary mirror to a focus behind the primary mirror. The objective may use all energy that is input into the objective to image a sample. The objective has demonstrated particular utility in the field of infrared spectroscopy of small samples.