Abstract:
A UV detector for liquid chromatography is equipped with a light source; a flow cell having a light entrance side and a light exit side; a first optical system for shining light from the light source into the flow cell so as to form an image roughly at the light exit side of the flow cell or at a position outside the flow cell at a prescribed distance away from the light exit side thereof; a light detector; a second optical system for directing light exiting the flow cell to the light detector; and a truncated cone shaped sample chamber formed in the flow cell along the axial direction thereof, with the base of the truncated cone being positioned at the light entrance side of the flow cell.
Abstract:
A charge balance type of photodiode array uses parallel A/D conversion in each channel of the photodiode array. The charge caused by the photocurrent of a photodiode in each channel is removed in predetermined charge packets provided by a dumping circuit and the binary encoded number of delivered charge packets corresponds to the actual photocurrent. Charge balance photodiode arrays have a wide variety of applications. It is therefore useful to adapt photodiode arrays to the specific requirements of an individual application. The intention therefore provides a photodiode array having at least one switching circuit to vary signal processing parameters such as a gain factor g or an attenuation factor k. This improvement facilitates a multifunctional photodiode array for a plurality of different applications.
Abstract:
An apparatus for detecting a centroid of a spot produced by electromagnetic radiation, e.g., optic radiation, using an array of PIN photodiodes serving as photodetectors and being organized in columns and in rows. Vertical connections are used to interconnect the PIN photodiodes in the columns in accordance with a first pattern that interconnects two or more adjacent columns. Horizontal connections are used to interconnect PIN photodiodes in the rows in accordance with a second pattern that interconnects two or more adjacent rows. The first and second patterns of interconnections can include just two adjacent columns and two adjacent rows, respectively and form a checkerboard interconnect pattern. The interconnections are made such that there are no anode connections between the PIN photodiodes in the rows and columns. The apparatus has a processing circuitry for rapidly deriving an X-extent of the centroid from current signals obtained from the columns and a Y-extent of the centroid from current signals obtained from the rows.
Abstract:
An apparatus for determining the light power level of a light beam (7), having a beam splitter (1) and a detector (11) associated with the beam splitter (1), is disclosed. The apparatus is characterized in that the beam splitter (1) splits measuring light (23) out of the light beam and conveys it to the detector (11), and that the ratio between the light power level of the light beam (7) and the light power level of the measuring light (23) measured at the detector (11) is constant over time.
Abstract:
A position measuring system for determining the relative position of a first object and a second object movable relative to one another that includes an incremental track, associated with a first object and having a periodic line structure that has individual lines and a scanning unit, associated with a second object movable relative to the first object, that scans said periodic line structure and that generates a corresponding incremental signal. A sensor system that generates absolute position information pertaining to the relative position of the first and second objects, wherein the width of the individual lines, as measured along a longitudinal direction of the incremental track, varies over at least a portion of the breadth of the incremental track, as measured in a direction transverse to the longitudinal direction, in such a way that a structure with absolute position information is superimposed on the periodic line structure.
Abstract:
Methods, apparatus, and systems, including computer program products, implementing and using techniques for measuring multi-channel single-shot transient signals. A signal acquisition unit receives one or more single-shot pulses from a multi-channel source. An optical-fiber recirculating loop reproduces the one or more received single-shot optical pulses to form a first multi-channel pulse train for circulation in the recirculating loop, and a second multi-channel pulse train for display on a display device. The optical-fiber recirculating loop also optically amplifies the first circulating pulse train to compensate for signal losses and performs optical multi-channel noise filtration.
Abstract:
An apparatus for collecting and sensing light in a projector, comprising a cold mirror positioned directly in the incident light path from a lamp and illumination optics of the projector for reflecting a large portion of visible light towards a light imaging device while transmitting IR and UV light and a small portion of the visible light; a secondary mirror for reflecting the small portion of the visible light, an integrating box positioned to collect and integrate the small portion of visible light, a light tube in optical communication with the integrating box for further integrating and attenuating the small portion of visible light, and an electro-optic device within the light tube for measuring the small portion of visible light within the light tube and generating an electrical signal in response thereto.
Abstract:
An apparatus for expeditiously irradiating an object with ultraviolet radiation at a selected UV wavelength. The apparatus includes a plurality of ultraviolet sources, each emitting radiation at a first wave length. The UV sources are mounted within a housing that also supports one or more conversion plates that can be interposed between the UV sources and the specimen and function to convert the UV to a second wavelength.
Abstract:
A beam characterization monitoring apparatus receives an input VUV beam and measures a beam profile characteristic of the beam. An enclosure has an interior substantially free of VUV photoabsorbing species and configured for receiving the input VUV beam therein. Optics within the enclosure separate the input VUV beam into a first component for measuring a near field beam profile characteristic and a second component for measuring a far field beam profile characteristic. A detector coupled with the enclosure via a beam path substantially free of VUV photoabsorbing species preferably detects the first and second components simultaneously. A quantum converter is preferably disposed along the beam path before the detector for converting the VUV beam to a beam having a wavelength above 240 nm. A second detector preferably detects an energy of an additional component of the input VUV beam.
Abstract:
Fiber grating environmental measurement systems are comprised of sensors that are configured to respond to changes in moisture or chemical content of the surrounding medium through the action of coatings and plates inducing strain that is measured. These sensors can also be used to monitor the interior of bonds for degradation due to aging, cracking, or chemical attack. Means to multiplex these sensors at high speed and with high sensitivity can be accomplished by using spectral filters placed to correspond to each fiber grating environmental sensor. By forming networks of spectral elements and using wavelength division multiplexing arrays of fiber grating sensors may be processed in a single fiber line allowing distributed high sensitivity, high bandwidth fiber optic grating environmental sensor systems to be realized.