Abstract:
An improved echelle spectrometer comprises a slit in light blocking plate, an echelle grating, and a detector array. The slit is shaped and oriented to align an image of a light beam projected through the slit, onto the echelle grating and onto the detector in a desired orientation and shape relative to the detector array. Precise adjustment of the shape and orientation of the slit is dependent on the orientation of the detector with respect to the dispersion direction of the echelle grating. The echelle spectrometer provides high detector resolution with reduced read-out time.
Abstract:
The instant invention relates to a process and apparatus for atomic absorption analysis, utilizing: atomization of a sample (containing one or more elements), illuminating the atomized sample with a continuum light source to produce a resultant light, directing the resultant light through a light dispersing means, detection of light at the focal plane of the light dispersing means using an integrating array detector (e.g. linear photodiode array) for converting the incident light into amplified electrical signals, blocking the incident light from striking the detector means and during this blocking utilizing the detector means to convert integrated intensities into amplified electrical signals, and deriving from these signals a value proportional to concentration. The present invention permits the aforementioned analysis to be performed at a very high rate i.e. at least 40 times per second.
Abstract:
The invention refers to a device for investigating highly resolved partial spectra of an echelle spectrum, being applicable to the simultaneous determination of the intensities of different spectral elements of a radiation spectrum produced by an echelle spectrometer. The device consists of a position-resolving photoelectric detector including several photosensors arranged on an IC chip, where said photosensors are arranged on the chip surface discretely at the positions of preselected spectral lines, each of the photosensors consisting of a CCD sensor row and a logic circuit which, depending on activation levels, enables supply potentials and clock signals to be connected and output signals to be transferred to a common output signal line; the areas of the individual sensor elements of the CCD sensor rows being matched to the spectral elements of the echelle spectrum and extending successively in the direction of dispersion of the echelle grating; the total number of sensor elements of all CCD sensor rows on the chip being smaller than the number of spectral elements in the echelle spectrum; and a digital logic circuit enabling, by means of the activation levels managed by it, the serial readout of the signals from a selsotable subset of all CCD sensor rows in a selectable order of succession, via the common output signal line, depending on external control signals.
Abstract:
A pair of optical beams of radiant energy from separate paths in a spectrophotometer are coaxially merged into a single composite beam with an optical member which resembles a coarse echelette grating. A reflective surface which includes the surfaces of sidewalls within a plurality of parallel grooves is disposed on the optical member. The grooves are arranged in a lateral array and are generally V-shaped cross-sectionally. The beams to be combined are directed upon the sidewalls and the composite beam is emitted therefrom in accordance with the law of reflection. When the beams to be combined include non-collimated rays, shadowing is provided by the portion of the optical member between adjoining sidewalls of adjacent grooves to reduce flare. Furthermore, image aberrations as caused by off-axis operation due to use of a spherical mirror in the beam combining arrangement, are substantially corrected by the optical member.
Abstract:
A method for focusing the horizontal and vertical components of energy reflected from an echelle grating which includes rotating the grating about a first axis substantially parallel to a prism face and rotating the grating about a second axis substantially normal to the first axis.
Abstract:
The invention relates to a measuring device for reading out measuring sensors disposed in a fiber optical waveguide. The measuring device comprises a grid array which distributes an input signal generated by the measuring sensors to different outputs. The transmission characteristics (12) associated with the outputs have as large an overlap region as possible so as to increase the measuring range of the measuring device.
Abstract:
Ein Verfahren zur Untergrundbestimmung und- Korrektur von breitbandigem Untergrund, ist gekennzeichnet durch die Schritte: Glätten der aufgenommenen Spektralkurve; Bestimmen aller Werte der ursprünglichen Kurve, deren Wert über dem Wert der geglätteten Kurve liegt, und Reduzierung dieser Werte auf den Wert der geglätteten Kurve; wenigstens zweifaches Wiederholen der Schritte und Subtraktion der auf diese Weise erhaltenen Untergrundkurve von der ursprünglichen Kurve. Das Glätten der Kurve kann mittels Moving Average erfolgen. Die Breite des Moving Average kann das Doppelte einer durchschnittlichen Linienbreite einer Referenzlinie betragen.
Abstract:
Ein Verfahren zur Wellenlängenkalibrierung von Echellespektren, bei denen sich die Wellenlängen auf eine Mehrzahl von Ordnungen verteilen, ist gekennzeichnet durch die Schritte: Aufnehmen eines linienreichen Referenzspektrums mit bekannten Wellenlängen für eine Vielzahl der Linien, Bestimmen der Lage einer Vielzahl von Peaks des Referenzspektrums in dem aufgenommenen Spektrum, Auswählen von wenigstens zwei ersten Linien mit bekannter Ordnung, Lage und Wellenlänge, Bestimmen einer Wellenlängenskala für die Ordnung, in welcher die bekannten Linien liegen, durch eine Fitfunktion λ m (x), Bestimmen einer vorläufigen Wellenlängenskala λ m±1 (x) für wenigstens eine benachbarte Ordnung m±1 durch Addition/Subtraktion einer Wellenlängendifferenz Δλ FSR , die einem freien Spektralbereich entspricht nach λ m±1 (x) = λ m (x) ± Δλ FSR , mit Δλ FSR =λ m (x)/m, Bestimmen der Wellenlängen von Linien in dieser benachbarten Ordnung m±1 mittels der vorläufigen Wellenlängenskala λ m±1 (x), Ersetzen der vorläufigen Wellenlänge von wenigstens zwei Linien durch die nach Schritt (a) vorgegebene Referenzwellenlänge dieser Linien, und Wiederholen der Schritte (d) bis (g) für wenigstens eine weitere benachbarte Ordnung.
Abstract:
The invention relates to a spectrometer arrangement (10) comprising a spectrometer (14) for producing a spectrum of a first wavelength range of radiation from a radiation source on a detector (42). Said arrangement also comprises: an Echelle grating (36) for the spectral decomposition of the radiation penetrating the spectrometer arrangement (10) in a main dispersion direction (46); a dispersing element (34) for separating the degrees by means of spectral decomposition of the radiation in a transversal dispersion direction (48) which forms an angle with the main dispersion direction of the Echelle grating (36), in such a way that a two-dimensional spectrum (50) can be produced with a plurality of separated degrees (52); an imaging optical element (24, 38) for imaging the radiation penetrating through an inlet gap (20) into the spectrometer arrangement (10), in an image plane (40); and a surface detector (42) comprising a two-dimensional arrangement of a plurality of detector elements in the image plane (40). The inventive arrangement is characterised in that another spectrometer (12) comprising at least one other dispersing element (64) and another imaging optical element (60, 66) is provided in order to produce a spectrum (68) of a second wavelength range of radiation, which is different from the first wavelength range, from a radiation source on the same detector (42). The spectra can be spatially or temporally separated on the detector.