Abstract:
Bei einem Verfahren zum spektral aufgelösten Messen optischer Eigenschaften von Proben wird eine Probe in einer Messposition angeordnet, es mittels einer Lichtquelle Licht erzeugt. Spektrale Anteile des Lichts werden als Anregungslicht in einem ersten optischen Pfad zu der Probe übertragen. Durch die Probe emittiertes oder transmittiertes Licht wird in einem zweiten optischen Pfad zu einem Detektor übertragen. In dem ersten optischen Pfad und/oder in dem zweiten optischen Pfad ist ein durchstimmbarer Monochromator angeordnet. Ein Spektrum des emittierten oder transmittierten Lichts wird über einen effektiven Spektralbereich (SPE) durch Verschieben eines spektralen Passbereiches des durchstimmbaren Monochromators aufgenommen. Das Verfahren ist dadurch gekennzeichnet, dass Licht in Form von Lichtpulsen mit vorgebbarer Pulsfrequenz genutzt wird, dass der spektrale Passbereich des durchstimmbaren Monochromators für die Aufnahme eines Spektrums mit einer Verschiebungsgeschwindigkeit kontinuierlich von einer Anfangswellenlänge zu einer Endwellenlänge verschoben wird und dass die Pulsfrequenz des Lichts mit der Verschiebungsgeschwindigkeit des spektralen Passbereichs über eine Steuerung derart synchronisiert wird, dass innerhalb des effektiven Spektralbereichs (SPE) eine Vielzahl von Messungen des emittierten oder transmittierten Lichts an einer entsprechenden Vielzahl von spektralen Stützpunkten (ST1, ST2, STn) erfolgt.
Abstract:
Provided is a Fourier transform type spectrophotometer capable of stably controlling a speed of a moving mirror. The Fourier transform type spectrophotometer according to the present invention is provided with a movable unit 111 to which a moving mirror 141 is fixed, outside-force-applying means 160 configured to apply external force larger than movement resistance of the movable unit 111 to the movable unit 111, a driving source 120 configured to apply positive or negative driving force along the moving direction of the movable unit 111 to the movable unit 111, a speed measurement unit 132 configured to measure the moving speed of the movable unit 111, and a driving force control unit 131 configured to control the driving force of the driving source 120 so that the movable unit 111 is moved in a predetermined manner based on the moving speed, wherein a rate of fluctuation of the driving force is suppressed by operating in a state in which the driving force of the driving source 120 is high due to the external force to thereby stabilize the control.
Abstract:
A system and method of high-speed microscopy using a two-photon microscope with spectral resolution. The microscope is operable to provide two- to five-dimensional fluorescence images of samples, including two or three spatial dimensions, a spectral dimension (for fluorescence emission), and a temporal dimension (on a scale of less than approximately one second). Two-dimensional (spatial) images with a complete wavelength spectrum are generated from a single scan of a sample. The microscope may include one of a multi-beam point scanning microscope, a single beam line scanning microscope, and a multi-beam line scanning microscope. The line scans may be formed using one or more of curved mirrors and lenses. The multiple beams may be formed using one of a grating, an array of lenses, and a beam splitter.
Abstract:
A transmission Raman spectroscopy apparatus has a light source for generating a light profile on a sample, a photodetector having at least one photodetector element, collection optics arranged to collect Raman scattered light transmitted through the sample and direct the Raman light onto the at least one photodetector element and a support for supporting the sample. The support and light source are arranged such that the light profile can be moved relative to the sample in order that the at least one photodetector element receives Raman scattered light generated for different locations of the light profile on the sample.
Abstract:
In determining whether an object contains e.g. a hazardous substance or molecules of a hazardous substance the object is illuminated with light of a definite wavelength. A telescope collects and concentrates light scattered by the object and a plurality of individual picture elements in a picture element array in a camera receives and detects the collected and concentrated light. The detection signals from each of the individual picture elements are individually analyzed to produce a Raman-spectrum or some similar spectrum valid for the subarea of the illuminated area of the object that corresponds to the respective picture element. The subarea of the illuminated area that corresponds to one of the individual picture elements can be chosen to have a width or dimension chosen to correspond to the size or a dimension of a particle or a molecule of the hazardous substance. A filter that can be tunable can be used for filtering the collected and concentrated light before being received by the camera, so that at each instance light of only one wavelength range is detected.
Abstract:
The invention relates to a surface refractive index scanning system for characterization of a sample. The system comprises a grating device for holding or receiving the sample, the device comprising at least a first grating region having a first grating width along a transverse direction, and a second grating region having a second grating width in the transverse direction. The first grating region and the second grating region are adjacent in the transverse direction, wherein the first grating region has a grating period Λ1 in a longitudinal direction, and the second grating region has a grating period Λ2 in the longitudinal direction, where the longitudinal direction is orthogonal to the transverse direction. A grating period spacing ΔΛ=Λ1-Λ2 is finite. Further, the first and second grating periods are chosen to provide optical resonances for light respectively in a first wavelength band and a second wavelength band, light is being emitted, transmitted, or reflected in an out-of-plane direction, wherein the first wavelength band and the second wavelength band are at least partially non-overlapping in wavelength. The system further comprises a light source for illuminating at least a part of the grating device with light at an illumination wavelength band. Additionally, the system comprises an imaging system for imaging the emitted, transmitted or reflected light from the grating device. The imaging system comprises an optical element, such as a cylindrical lens or a bended mirror, configured for focusing light in a transverse direction and for being invariant in an orthogonal transverse direction, the optical element being oriented such that the longitudinal direction of the grating device is oriented to coincide with the invariant direction of the optical element, and an imaging spectrometer comprising an entrance slit having a longitudinal direction oriented to coincide with the invariant direction of the optical element. The imaging spectrometer further comprises a 2-dimensional image sensor. The invention further relates to a method.
Abstract:
A Micro-Electro-Mechanical System (MEMS) interferometer provides for self-calibration of mirror positioning of a moveable mirror. The moveable mirror is coupled to a MEMS actuator having a variable capacitance. The MEMS interferometor includes a capacitive sensing circuit for determining the capacitance of the MEMS actuator at two or more known positions of the moveable mirror and a calibration module for using the actuator capacitances at the known positions to compensate for any drift in the capacitive sensing circuit.