Abstract:
An optical system for a multidetector array spectrophotometer which includes multiple light sources for emitting light of selected wavelength ranges and means for selectively transmitting the selected wavelength ranges of light to respective slits of a multi-slit spectrograph for multiple wavelength range detection. The spectrograph has two or more slits which direct the selected wavelength ranges of the light spectra to fall upon a dispersive and focusing system which collects light from each slit, disperses the light by wavelength and refocuses the light at the positions of a single set of detectors.
Abstract:
An improved spectrophotometer, especially suitable for use in centrifugal analysis instrumentation, is disclosed. The spectrophotometer is improved by including therein a detector comprising a photodiode array assembly having a photodiode array, a spectral filter assembly situated substantially parallel thereto and in the path of incident light and means for attenuating stray light which would otherwise impinge on each of the photodiodes of the array.
Abstract:
A temporal spectral photometer for use in obtaining spectral and temporal information simultaneously of an ultrafast pulse of luminescent light emitted from a sample upon excitation thereof includes an excitation section and a detection section. The excitation section includes a picosecond laser for exciting the sample to emit luminescent light and imaging optics for imaging the emitted light. The detection section includes a pin hole slit through which light from the imaging optics is admitted, a streak camera tube, an optical system including a grating for forming an image of the pin hole slit on the photocathode of the streak camera tube and at the same time dispersing the light admitted through the pin hole slit into its component wavelengths, a micrometer assembly mechanically coupled to the grating for selectively changing the wavelength region of dispersed light impinging on the photocathode, a video camera, a camera lens system for imaging the output image formed on the phosphor screen of the streak camera tube onto the input end of the video camera, a digital temporal analyzer coupled to the output of the video camera for digitizing and analyzing image information from the video camera and a video monitor coupled to the output of the temporal analyzer for displaying the analyzed data.
Abstract:
An adjustable slit plate assembly for a monochromator is formed by two identical metal plates (P1, P2) each having a set of slits (EX1 to EX6 and EN1 to EX6 respectively) with all the slits disposed on a common circle. The plates (P1, P2) are located and supported on a disc (SM) on a rotatable shaft (SH) at the axis (A) of the circle. The slits are each of minimum length to pass a radiant beam of given energy through the monochromator and each set of slits occupies an arc of substantially minimum length. The shape of each plate is substantially a sector of a further circle whose radius and arc are the minimum necessary to accommodate the slits and the axis. The complete configuration of the plates is formed by etching in a single operation, and a greater number of slit sets can be formed together from a plate of given area than for the prior art case in which the two sets of slits for a slit assembly are formed in a single plate in the shape of a complete disc. A significant cost reduction in the slit assembly is thus achieved.
Abstract:
An apparatus for measuring a diamond color comprises a light source composed of a lamp and an integrating sphere for diffusing light therein emitted from the lamp; a diamond holder including diamond supporting head means and suction base means, thereby positioning the table facet of the diamond in the integrating sphere for allowing the diffused light from the light source to fall on the table facet of the diamond; a monochromator for separating a beam of light as it emerges from the diamond through the table facet side into a spectrum; a photodetector for detecting the light from the monochromator; variable slit means disposed in at least one of the monochromator and the photodetector for adjusting the size of the beam of light to a diameter of the diamond; a measurement unit for controlling at least the monochromator to obtain a spectrum of the light which has passed through the diamond; and an arithmetic unit for deriving tristimulus values X, Y and Z from the spectrum of the light from the diamond; which is able to measure the colors of brilliant-cut diamonds easily and objectively.
Abstract:
Optical spectroscope for scanning electron microscopes, the latter comprising a vacuum chamber containing a sample holder bombarded by an electron beam.The microscope chamber contains a concave mirror having an opening, a plane deviating mirror and an exit window for the chamber. Outside the microscope chamber is provided a drum carrying a plurality of flat diffractive gratings, the drum being equipped with a bracket which rotates about an axis controlled by a stepping motor. In addition there are a spherical concave mirror, a slit blocking means and a photodetector.
Abstract:
A dispersive optical spectrometer is disclosed which comprises light detection means, dispersion means for separating light radiation into spectral components and for directing the spectral components toward the light detection means, means for admitting light radiation into the entrance focal plane and for directing the light radiation toward the dispersion means, the light radiation admitting means including a plurality of spaced-apart apertures, and light transmission means for transmitting light radiation from a light source to one or more of the apertures.
Abstract:
A spectrometer of the Rowland circle type having an annular steel table on which are supported a plurality of wheeled carriages. Each carriage has a remotely operable magnetic clamping arrangement to clamp it to the table. Each carriage also has a light entrance slit located in the focal plane, a photo-multiplier tube, and an optical fibre for channelling light from the entrance slit to the photo-multiplier tube. A positioning arm, pivotal about a central axis, is provided. The arm has at its free end a gripping arrangement which is remotely operable to grip any selected carriage. The arm is also remotely positionable to any position on the circle so that any particular carriage can be engaged; displaced to any desired new position; disengaged; and left clamped in the new position. An arcuate rule with an optical read head is also provided whereby the position of the arm is determined. The arm and the carriages are in an evacuated and thermally and structurally insulated housing.
Abstract:
The slit assembly of the present spectrometer comprises a liquid crystal cell. The electrodes of the cell are selectively actuated for producing a pattern of slits appropriate to the spectral lines of interest in the spectrum derived from the substance under analysis.
Abstract:
Apparatus for controlling the width of an adjustable slit in response to the product of two variable functions, one of which is programmed, which includes at least one adjustable optical slit; slit width programming apparatus for producing a first displacement that is a logarithmic function of the instantaneous slit width conforming to a predetermined program; antilogarithm generating elements for producing a second displacement that is the antilogarithm of the first displacement; a phase adjusting mechanism for controlling the phasing between the first displacement and the second displacement; slit width selection apparatus operative on the phase adjusting mechanism for controlling the phasing in accordance with a given slit width selection; and actuating elements responsive to the second displacement and operative on the optical slit for controlling its width.