Abstract: A method in which a multiplicative ratio approach is used to remove the effects of the unwanted background fluorescence when making fluoroescence polarization (FP) measurements rather than the conventional subtractive approach, thus preserving both the precision and accuracy of the FP measurements, is disclosed. The method comprises selecting an appropriate multiplicative ratio, then calculating the selected multiplicative ratio using sample measurements. The calculated multiplicative ratio is multiplied by an appropriate value in a standard FP measurement equation or an appropriate value in an equation derived from a standard FP measurement equation. After this, the corrected FP measurement is calculated. When such multiplicative ratios are applied to the appropriate value or values in an FP measurement equation, the effects of background noise can be reduced without decreasing the precision of the FP measurements.

Abstract: The long-term stability of the analytic accuracy of spectroscopic measurements is often limited by wavelength axis instabilities of the hardware. A dedicated optical element called the inverse sample element (4) is inserted into the path of the measurement light. The optical response of the inverse sample element (4) is determined from the spectral response of the average sample (3) in such a way that wavelength axis instabilities of the instrument hardware cause opposite and nearly cancelled amplitude effects in the resulting absorbance spectrum. The inverse sample element (4) can be movable or permanently mounted inside the instrument and is preferably made from a thin-film structure.

Abstract: The indication of correct color evaluation standards of a printed matter including a paper containing a fluorescent whitening agent, is enabled even in the case where the printed matter is observed under a light source that differs from the light source used for color measurement. A spectral reflectance Pt(&lgr;) of the paper under a light source T and a spectral reflectance Pu(&lgr;) of the paper under a light source U are measured in advance and a differential component, due to the fluorescent whitening agent, is determined as Fp(&lgr;)=Pu(&lgr;)−Pt(&lgr;). For a printed matter of dot percent S, a spectral reflectance Rt(&lgr;, S) under light source T is measured, and the measured values are subject to a correction process of adding an effective component within the differential component Fp(&lgr;) that is in accordance to dot percent S to determine an estimated spectral reflectance Rtu(&lgr;, S) under light source U.

Abstract: A small-spot imaging, spectrometry instrument for measuring properties of a sample has a polarization-scrambling element, such as a Lyot depolarizer, incorporated between the polarization-introducing components of the system, such as the beamsplitter, and the microscope objective of the system. The Lyot depolarizer varies polarization with wavelength. Sinusoidal perturbation in the resulting measured spectrum can be removed by data processing techniques or, if the depolarizer is thick or highly birefringent, may be narrower than the wavelength resolution of the instrument.

Abstract: System and method for simultaneously providing a wavelength spectral distribution and a temporal distribution of an incident light beam. The light beam is received at a wavelength spectral distribution module and is separated into light beam segments corresponding to at least two different wavelengths in a first selected direction transverse to beam propagation direction. The light beam is also received at a temporal distribution module, and segments of the light beam are distributed corresponding to at least two different times at which light in the beam was produced, in a second selected direction that is substantially perpendicular to the first direction. The temporal distribution module may include a rotating segmented mirror.

Abstract: An arrangement for wavelength-dependent adjustment of light beam, preferably laser radiation of different wavelengths, preferably in a laser scanning microscope, wherein the light beam is split by a dispersive element and reaches a concave mirror, and an adjustable device for at least partially cutting out individual wavelengths or wavelength ranges of the incident and/or reflected beam is located in front of the concave mirror.

Abstract: A device for detection of one or several fluorescent species, said species being contained in a medium, said medium being contained in a conduit, said device comprising a means of exciting the fluorescent species by light, said medium and conduit making up a structure that is transparent to the exciting and the emitted fluorescent light, and said device comprising one or several such structures, may be improved by letting at least part of the emitted fluorescent light be guided away from the illumination zone by total internal reflection (TIR) in said structure and collected from one end of said structure.

Abstract: A diffraction grating and a prism with the appropriate characteristics are employed to provide a combined dispersive characteristic that is substantially linear over the visible spectrum. Radiation from the grating and prism is collimated by a lens towards a detector array. The grating or a telecentric stop between the grating and prism is placed at a focal point of the lens in a telecentric arrangement so that equal magnification is achieved at the detector array. If the detector array is replaced by a plurality of optical channels, a multiplexer/demultiplexer is obtained.

Abstract: An object of inside-quality inspection being conveyed on a conveyer is irradiated sideways with beams of light from projection lamps concentratedly. A photodetecting device detects light transmitted through the object irrespective of the size and thickness of the skin of the object without being influenced by extraneous light. A white-level calibrating device is provided to the photodetecting means. The projection lamps project and concentrate their beams of light onto one side of the object in an inspection position at different angles from different positions diagonally distributed from the oblique front to the oblique back. Fractions of light transmitted through the object and emerging from the other side of the object are condensed by a condenser lens A shutter for opening/closing the optical path is provided between a light receiving window of the condenser lens and a light-inputting face of an optical fiber for directing light to a spectrometer.

Abstract: A planar spectrograph for demultiplexing optical wavelength signals includes a monolithic substrate. The substrate has a diffraction grating etched therein. The diffraction grating is integrally formed in the substrate to be in operative relationship with input light to diffract and reflect the input light to a detector. A recess is formed in the substrate to accommodate a separate slab waveguide. A slab waveguide is dimensioned and configured to fit within the recess, and the waveguide guides input light to and from the diffraction grating. A silicon-on-insulator spectrographs is also described, as well as, fabrication processes for manufacturing these spectrographs.

Abstract: The invention concerns an apparatus for optically characterising a thin-layer material by backscattering Raman spectometry comprising a frame, a monochromatic excitation laser source (21), optical means (23, 24) directing a light flux emitted by the source towards the material to be characterised, provided with means (22) homogenising the distribution of energy per surface unit, over a minimum surface of some tens of square micrometers, and means for collecting (24) and selecting (27, 28) the light diffused by Raman effect. The apparatus further comprises reflectometric measuring means (3-14) integral with the Raman measuring means, including reflectometric excitation means (3-9) directed on the same sample zone as the Raman excitation means.

Abstract: Systems and methods are described that may be applied to scanning biological materials in or on probe arrays. For example, a system is described that includes a scanner that has one or more excitation sources and an emission receiving element, such as an objective lens, that receives from locations of the probe array an emission signal responsive to the excitation sources. The scanner also has a radial position generator that generates radial positions of the emission receiving element. Also included in the system is a computer memory having stored therein a plurality of position data, each representing a radial position of the emission receiving element. Also stored in the computer memory unit is a set of comparator instructions that generate a clock signal based, at least in part, on comparing one or more of the plurality of radial positions with one or more of the plurality of position data.

Abstract: The invention relates in general to calibrating a focused beam of energy in a solid freeform fabrication apparatus, and, in particular, to a method of measuring the propagation characteristics of the beam to produce beam propagation data. The beam propagation data can be used to verify that the beam is operating within tolerance, and/or produce a response that can be used to further calibrate the beam. The invention is particularly useful in determining asymmetric conditions in the beam. The beam propagation data is produced in accord with the “M2” standard for characterizing a beam. In one embodiment, the response indicates the beam is unacceptable for use in the apparatus. In another embodiment, the response is provided to calibrate the focal position of the beam. In still another embodiment, the response is provided to an adjustable beam that eliminates the asymmetric condition.

Abstract: An apparatus is described that includes an emission signal detector and an emission signal filter. An excitation beam scans an array of biological materials, and the emission signal detector detects an emission signal indicative of an emission beam responsive to the excitation beam. The emission signal filter is a linear-phase filter that provides a filtered emission signal having substantially symmetrical rise and fall edges. A linear-phase excitation signal filter may also be provided that provides a filtered excitation signal having substantially symmetrical rise and fall edges. The emission signal filter and the excitation signal filter may be matched. In some applications, they may be high-order Bessel filters. Linear-phase filtering enables sampling of emission signals to be accomplished consistently irrespective of the scanning direction, and thus is particularly advantageous in bi-directional scanning applications.

Abstract: Apparatus and method for inspecting thin film specimens along a line. A laser emits pulses of light that are split into first, second, third and fourth portions. A delay is introduced into the first portion of pulses and the first portion of pulses is directed onto a thin film specimen along a line. The third portion of pulses is directed onto the thin film specimen along the line. A delay is introduced into the fourth portion of pulses and the delayed fourth portion of pulses are directed to a photorefractive crystal. Pulses of light reflected from the thin film specimen are directed to the photorefractive crystal. Light from the photorefractive crystal is collected and transmitted to a linear photodiode array allowing inspection of the thin film specimens along a line.

Abstract: The present invention is directed to asynchronous scanning devices and methods of using asynchronous scanning to acquire fluorescence data from a sample, such as biological tissue, to facilitate diagnosis of the presence or absence of disease or other abnormality in the sample. The present invention is useful for biomedical diagnostics, chemical analysis or other evaluation of the target sample.

Abstract: A system and method for fast peak finding in an optical spectrum prioritizes the information it first generates and how the information is then forwarded from the system to a host computer, for example. A spectrum detection subsystem generates a spectrum of an optical signal. An analog-to-digital converter converts the spectrum into sample data. Finally, a data processing subsystem first detects the spectral locations of peaks in the spectrum using the sample data and then uploads the peak information to a host computer before performing processing to determine the shapes of the peaks and/or noise information for the optical signal, for example. The system is thus able to quickly find some information, such as whether or not channels or carriers are present, at what frequency the carriers are operating, and the carriers' power level, and send this information to the host computer. In contrast, information concerning spectral shape or the noise floor is sent later in time.

Abstract: An optical spectrum analyzer comprises a diffraction grating (DG), a polarization decomposing unit (PDM) for decomposing the input light beam into first and second light beams having mutually-perpendicular linear states of polarization, and two output ports (FP2/1, FP2/2) each for receiving from the grating, substantially exclusively, a respective one of the polarized light beams (LT, LR) after diffraction by the diffraction grating (DG).

Abstract: In a method of determining the shade stability of paints, the total color difference &Dgr;E(FT) between the color at the film thickness FT and the color at a predetermined film thickness FT0 is measured for different film thicknesses FT. Subsequently, the slope &sgr;(FT) of the plot &Dgr;E(FT) is determined, which represents a useful parameter for the shade stability. Alternatively to &sgr;(FT), it is also possible to determine the limiting film thickness FTlim at which the total color difference &Dgr;E(FT) passes below a predetermined limit. The method of determining the shade stability is additionally employed in order to optimize paint formulations.

Abstract: The Ebert-type mounting is modified for use as a multiorder spectrograph, by replacing the spherical primary mirror of the Ebert with a paraboloidal mirror to eliminate the astigmatism and spherical aberration of the Ebert mounting, and by replacing the Ebert's rotating plane grating, normally blazed for use in the first order, with a fixed low-blaze-angle grating blazed at a longer wavelength such that the radiation at the shorter wavelengths, for which the grating will be used, will be most efficiently dispersed into a multiplicity of higher spectral orders. In a preferred embodiment of this invention, these spectral orders are separated using a twice-through cross-dispersing prism mounted near the grating surface, with the grating and prism mounted and aligned together in a crossed-dispersion assembly that is interchangeable with other crossed-dispersion assemblies containing other grating and prism combinations.