Abstract:
In order to identify specific objects such as diamonds 2 in gangue on a conveyor belt, a line across the conveyor belt is irradiated with X-rays so that wanted particles 2 luminesce, and the luminescence is detected using an optical system 5 and a photo-multiplier tube 6. The response of the photo-multiplier tube 6 is scanned so that the location from which the luminescence was omitted is determined from the position of the scan at the instant of detection. The arrangement is useful for sorting minerals, including diamond, which luminesce.
Abstract:
In order to identify diamonds in gangue, incident laser radiation is scanned along an extended line across particulate gangue, and the diamonds 2 are identified by detecting the Raman radiation which is emitted, using a narrow pass band filter 9 in order to block out other radiation. In order to identify the position along the scan line from which the Raman radiation was emitted, the incident laser radiation is pulsed at a pulse frequency which changes along the scan line, and the frequency of the Raman radiation detected is sensed. In this way, one can simplify the equipment needed.
Abstract:
L'invention concerne un système de détection à distance du coefficient d'atténuation diffuse ou facteur K sur de très grandes zones et sur des périodes relativement courtes, et pour la détermination de la profondeur dans un plan d'eau ou autre milieu. Selon la présente invention, on utilise un laser pour générer de courtes impulsions de lumière ayant des largeurs d'impulsions de l'ordre des nanosecondes. La lumière du laser est expansée par un système optique et est projettée dans l'eau ou autre millieu. Une caméra CCD (dispositif à couplage de charge) intensifiée est obturée électroniquement après une temporisation appropriée de sorte que l'image formée par la caméra est composée de la lumière rétrodiffusée par l'eau d'une couche de portée z et d'épaisseur DELTAz. Le signal détecté par la caméra est Si. Si plusieurs mesures de Si sont effectuées à des différences de temporisation connues de sorte que les différences des portes de portée zi sont également connues, alors on peut calculer K. Le même appareil peut également être utilisé pour déterminer la profondeur en mesurant la temporisation entre la réflexion de la surface du milieu et la réflexion du fond du milieu
Abstract:
A system is presented for the remote detection and imaging of objects at night. In accordance with the present invention, a laser is used to generate short pulses of infrared light with pulse widths on the order of nanoseconds. The laser light is expanded by optics and projected at the target scene. An intensified CCD (charge coupled device) camera is electronically shuttered after an appropriate time delay such that the image formed by the camera is composed of infrared light backscattered by the target from a range of r.
Abstract:
In order to separate diamonds from gangue, the particles 2 of the gangue are carried along a belt 1, and are irradiated with a beam from a laser 3. The luminescence emitted by the particles 2 is then detected by two spaced optical modules 5,5′. The difference in the luminescence detected is related to the nature of the material, and a simple microprocessor 11 and ejection jet 12 can be used to eject diamonds into a sort bin.
Abstract:
In order to identify specific objects such as diamonds 2 in gangue on a conveyor belt, a line across the conveyor belt is irradiated with X-rays so that wanted particles 2 luminesce, and the luminescence is detected using an optical system 5 and a photo-multiplier tube 6. The response of the photo-multiplier tube 6 is scanned so that the location from which the luminescence was omitted is determined from the position of the scan at the instant of detection. The arrangement is useful for sorting minerals, including diamond, which luminesce.
Abstract:
An integrated circuit includes a photodetection region configured to receive incident photons. The photodetection region is configured to produce a plurality of charge carriers in response to the incident photons. The integrated circuit also includes at least one charge carrier storage region. The integrated circuit also includes a charge carrier segregation structure configured to selectively direct charge carriers of the plurality of charge carriers into the at least one charge carrier storage region based upon times at which the charge carriers are produced.
Abstract:
An optical pulse source 30 comprising a DPSS pump laser 31, a photonic crystal fibre (PCF) 35 and acousto-optic modulator (AOM) gating means 33. The pump pulses are coupled through lenses 32 to the AOM 33, synchronised to the pump laser 31 and operable to gate the pump pulses to a reduced repetition rate Rr = Rf/N, where Rf is the pump laser fundamental frequency. The pulses from the AOM 33 are injected via optics 34 into the PCF 35. Propagation through the PCF 35 causes the pulses to broaden spectrally to produce supercontinuum pulses. An optical pulse source comprising the optical pulse source 30 and an acousto-optical tunable filter (AOTF) operable to convert supercontinuum pulses into wavelength variable output pulses is also provided. A method of scaling the energy of the optical supercontinuum pulses is also provided.
Abstract:
An optical pulse source 30 comprising a DPSS pump laser 31, a photonic crystal fibre (PCF) 35 and acousto-optic modulator (AOM) gating means 33. The pump pulses are coupled through lenses 32 to the AOM 33, synchronised to the pump laser 31 and operable to gate the pump pulses to a reduced repetition rate Rr = Rf/N, where Rf is the pump laser fundamental frequency. The pulses from the AOM 33 are injected via optics 34 into the PCF 35. Propagation through the PCF 35 causes the pulses to broaden spectrally to produce supercontinuum pulses. An optical pulse source comprising the optical pulse source 30 and an acousto-optical tunable filter (AOTF) operable to convert supercontinuum pulses into wavelength variable output pulses is also provided. A method of scaling the energy of the optical supercontinuum pulses is also provided.