Abstract: A method of analysing a sample of biological material including components (2a to 2d) tagged with respective fluorescent labels (4a to 4d), comprises the steps of identifying a specific labeled component (2d) to be monitored, and irradiating with an energy beam at least one region (8) of the sample which substantially surrounds said specific component. The energy beam modifies the optical properties of labels in the region (8) such that they are distinguishable from the label (4d) associated with said specific component (2d). This assists the tracking of a specific component of interest as it moves through a sample. Apparatus for carrying out the method is also described.

Abstract: An infrared imaging microscope, particularly of the type used to carry out FT-IR measurement, including a detector in the form of a relatively small detector array of individual detector elements. The outputs of the detector elements are fed in parallel to an electronic circuit for processing. The relatively small array allows the outputs to be processed without need for multiplexing thereby avoiding reduction in signal-to-noise. The detector array may substantially range from about 3 to about 100 detector elements, and is preferably in a range from about 16 to about 64 detector elements.

Abstract: An accessory for a spectrometer for carrying out measurements of specular reflectance of a sample. The accessory is designed so that all components can be located in a housing and the sample can be located horizontally on a top-plate of the housing with the components disposed below the plane of that plate.

Abstract: A carrier for use in the preparation of samples for spectroscopic analysis comprises a generally planar body 10 the upper surface of which is formed with ridges or walls 14 which define compartments 15 into material to be analysed is spread. The surface of the compartments is preferably coated with a reflecting material such as aluminium. This form of carrier greatly facilitates the production of a layer of uniform thickness.

Abstract: A mounting arrangement for accurately orienting an optical component (10) with respect to an axis comprises three mounting elements arranged at the apices of a triangle, one of said mounting elements (16) is fixed whilst the other two (18, 29) are each provided on a pivotable mounting member 20. The mounting member (20) is arranged so that it can pivot against the resilience of a pivot mounting so that when a force is applied to the pivotable mounting member it is caused to pivot and thereby adjust the orientation of the component (10).

Abstract: Standardization is achieved for FTIR spectrometric instruments that effect an intrinsic distortion in spectral information, the distortion being associated with an aperture size. An idealized function of spectral line shape is specified. With a small calibration aperture, spectral data is obtained for a basic sample having known "true" spectral data, and standard spectral data also is obtained for a standard sample. With a larger, normal sized aperture, standard spectral data is obtained again for the calibration sample. A transformation factor, that is a function of this data and the standardized function, is applied to spectral data for test samples to effect standardized information. In another embodiment, the standard sample has known true spectral data, and the basic sample is omitted. In either case, the transformation factor is applied to the sample data in logarithm form, the antilogarithm of the result effects the standardized information.

Abstract: A probe for use in spectroscopic analysis comprises an optical fiber with a rod-like end piece. One form of the probe has a local detector which can be deposited on the end piece or located close to it. This improves collection efficiency of radiation diffusely scattered from a sample being investigated. An alternative arrangement uses a local source of radiation.

Abstract: Interferograms produced by a Michelson type interferometer used in Fourier Transform spectroscopy are processed by an arrangement which includes an analogue-to-digital converter (12) which is sampled by a fixed frequency clock signal to provide a digital representation of the interferogram. This signal is processed by a digital data processor (18) which also receives a digital representation of the reference fringe waveform to provide a digital output representing the interferogram. The digital representation of the reference fringe waveform may be produced by a second analogue-to-digital converter or by a timer. The analogue-to-digital converter may be arranged to produce oversampled representations of the interferogram or reference fringe waveforms. In one form of the invention the analogue-to-digital converter or converters include a delta sigma modulator.

Abstract: A carrier for use in the preparation of samples for spectroscopic analysis comprises a rod-like element 10 housing a domed end 11. The dome end 11 is coated with abrasive material. To prepare a sample the abrasive material is rubbed by linear movement or rotation against the material to be analysed. That material becomes abraded and attaches to the end 11. The carrier can be formed from a commercially available dowel and is therefore easy to make and use.

Abstract: A carrier for use in preparing samples for spectroscopic analysis comprises a layer of abrasive material, e.g. sandpaper, created with a highly reflective material e.g. aluminium. The novel carrier reduces the effect of unwanted spectral components generated by the grit particle of the abrasive.

Abstract: A method for determining concentration of an analyte in a sample includes generating a spectrum of a selected analyte and interferents, generating a spectrum of an unknown sample, computing first and second derivatives of the sample spectrum, deriving a matrix model that includes the analyte spectrum and the derivatives, and applying the matrix model to the sample spectrum so as to yield a parameter representing concentration of the selected analyte in the unknown sample. Multiple linear least squares regression is utilized to fit the model and calculate the parameter.

Abstract: A spectrometric instrument which exhibits an intrinsic profile for a sharp spectral line produces profile data for narrow spectral lines. The spectral lines are effected with a high finesse etalon of gold coated polymer. A transformation filter is computed for transforming the profile data to a gaussian profile. A wavelength calibration is combined with the filter to effect a correction matrix which is applied to sample data to generate calibrated standardized data. Iteratively a correction matrix is applied to calibration data to generate standardized calibration data which is utilized for the wavelength calibration. Calibration is effected with an optical standard, an interference etalon and a fringe formula. Etalon effective thickness is first estimated and then precisely determined so that fringe peaks calibrate wavelength.

Abstract: An optical transmittance apparatus has a pair of reference channels of glass rods and a pair of sample channels containing sample fluid. A beam splitter and mirror pass a first portion of an incident beam through an ingoing reference channel, and a second portion through an ingoing sample channel. The first portion is reflected back through an outgoing reference channel, and the second portion back through an outgoing sample channel. The beam splitter and mirror directs the outgoing beams into a common outlet path. A partial disk selectively passes either portion. For positioning the disk, poles of a magnet mounted on the disk axle face windings made about an axis perpendicular to the axle, the windings being on the opposite side of a barrier plate from the poles. Current of one polarity through the windings effects one orientation of the disk, and reversed olarity reorients it perpendicularly.

Abstract: In optical device for measuring displacement an optical grating is formed of alternating transparent and opaque stripes having equal widths. The grating is in an aperture plane with the stripes parallel to a central plane that is perpendicular to the aperture plane. Respective subpluralities of the stripes are located in an aperture area in the aperture plane, so that incident light rays on the aperture area are at least partially passed as beams by the transparent strips in the aperture area. A concave mirror has it center of curvature at the aperture area so as to return the beams back to the aperture area. The return beams are further passed by the transparent strips in the aperture area as return light. The grating is displaceable laterally to the cental plane, such that a corresponding responsiveness of the return light intensity to the lateral position provides a measure of displacement of the grating relative to the central plane. Alternative device with reflecting strips function similarly.

Abstract: An optical probe is for measurement of light transmission of liquid. A tubular housing three equally configured legs defining three arcuately spaced openings in the housing wall. A solid cylindrical member formed of glass or fused silica has a flat transparent end surface and an opposing curved surface silvered to form an internally concave reflector. The cylindrical member is retained in the housing with the transparent end surface adjacent to the openings. A transparent rod member has a flat first end surface and a flat second end surface parallel to the first end surface. The rod member is retained in the housing with the second end surface adjacent to the openings and spaced from the transparent end surface parallel thereto so as to define a cavity therebetween such that, upon immersion of the probe, liquid passes through the openings into the cavity. The first end surface is spaced from the concave reflector so that conjugate focal spots of the concave reflector are located at the first end surface.

Abstract: An optical switching device includes a first optical fiber terminating in a first window, and a plurality of second optical fibers each terminating in a corresponding second window. A concave mirror is selectively positionable with conjugate foci located respectively at the first window and selectively at any one of the second windows so as to reciprocally image the first window and a selected second window on each other. The imaging mirror is rotated about an axis spaced from and parallel to the optical axis of the mirror, so as to rotate the mirror among a plurality of arcuately spaced selected positions. In each selected position the imaging means closes a light circuit between the first optical fiber and a selected second optical fiber.

Abstract: In a method and a system for analyzing spectral data including a spectrophotometer and a spectral detector, a data station receives first transmittance spectrum data points and has a file register containing second transmittance spectrum data points. The first and second transmittance data points are transformed respectively to set of first and second absorbance spectrum data points. The first and second absorbance points are band pass filtered at a characteristic frequency nominally associated with spectral bandwidth so as to produce respective sets of first and second filtered data points. A set of weighting factors are established, each corresponding to the square of the sum of a first transmittance point and a second transmittance point for a selected frequency.

Abstract: A method identifies components in a sample by spectrally analyzing the sample in a spectrophotometer. The sample data points output from the spectrophotometer are detected in a detector before being stored in an array in a data station. A preselected smoothing bandwidth is entered into the data station from a keyboard. The bandwidth is converted to a strength parameter; and thereafter each of the smoothed data points is stored before being output as an array of smoothed data points to form a modified spectral display, which identifies the components in the sample.

Abstract: The invention is directed to a scanning Michelson type interferometer assembly which includes a beam splitter assembly for receiving a beam of radiation from a source, a stationary plane mirror for receiving and returning a first subbeam over a fixed optical path from the beam splitter assembly and an adjustable plane mirror for receiving and returning a second subbeam over a variable length optical path from the beam splitter, a system for receiving the combined output beam from the beam splitter assembly for forming a spectrum of the input beam radiation, a path difference generator having a pair of parallel spaced mirrors mounted so that the second subbeam is incident on one mirror and is reflected by both mirrors so as to emerage from this direction of incidence, the beam splitter assembly and the stationary plane mirror and the adjustable plane mirror as well as the optical path difference generator assembly being all mounted on a single, rigid monolithic structural frame to provide stability for the ent

Abstract: A preamplifier network or circuit for converting non-linear signal information, such as is produced by a mercury cadmium tellurium (MCT) detector, to a substantially linear voltage signal output corresponding to the incident light levels on the MCT detector. Conceptually speaking, the subject preamplifier functions as a constant-voltage variable-current source to the MCT detector, and incorporates positive feedback for being effective as a negative resistance to nullify the MCT detector resisance introduced signal component of the signal information being monitored.