Abstract:
The present invention relates to a laser device comprising at least one large area VCSEL (101) and at least one optical feedback element (201, 301) providing an angular-selective feedback for laser radiation emitted from the laser. The angular-selective feedback is higher for at least one portion of laser radiation emitted at angles ? > 0 to the optical axis (601) of the laser than for laser radiation emitted on said optical axis (601). The invention also refers to a method of stabilizing a laser emission of a large area VCSEL in a desired angular distribution (501, 502). With the proposed device and method, the intensity distribution of a large area VCSEL can be stabilized in a desired shape, for example a ring shape.
Abstract:
The present invention relates to an all-solid state UV laser system comprising at least one semiconductor laser (10) in a VECSEL configuration. The gain structure (3) in this semiconductor laser (10) emits fundamental radiation in a wavelength range which can be frequency doubled to wavelengths in the UV region. The frequency doubling is achieved with a nonlinear optical crystal (6) for second harmonic generation arranged inside the extended cavity of the semiconductor laser (10). By electrically pumping of the semiconductor laser wavelengths below 200 nm can be efficiently generated with already known semiconductor materials like GaN. The proposed UV laser system is compact and can be fabricated and operated at low costs compared to UV excimer lasers.
Abstract:
A flashlight comprising a mercury vapour discharge lamp (12) as e.g. a HID Lamp (High Intensity Discharge Lamp) with adjustable light output is described. The extreme brightness and peak intensity of mercury vapour discharge lamps (12) is enabled for signalling in mobile lighting applications without reducing the lifetime of the 5 mercury vapour discharge lamps (12).
Abstract:
The present invention relates to a detection device for detecting target substances in samples. The device comprises a substrate (1) with at least one planar waveguide laser (2) in or on said substrate (1), said waveguide laser (2) having a gain medium (5) for up-conversion or for down-conversion. A top layer (3) of said waveguide laser (2) forms at least part of a surface of said substrate (1) and allows formation of an evanescent wave in a sample contacting said surface. A structure is applied on said top layer (3) to define an array of probe regions (4) on said top layer (3), said probe regions (4) consisting of a coating of probe materials for sensing said target substances to be detected. The present detection device allows a parallel detection of target substances with a highly integrated design.
Abstract:
A surface-emitting extended cavity laser with intracavity frequency conversion is provided with at least one surface-emitting laser element (1) with multiple layers to obtain laser light at a fundamental frequency, reflector means, spaced from the laser element (1) to form an external cavity (12), a frequency conversion device (3), arranged within the external cavity (12) to generate light at a second frequency and tuneable optical band-pass filter means, arranged within the external cavity (12) and detector means, where said optical band-pass filter means are tuneable upon a signal, which is obtained by the detector means to enable a frequency control at the fundamental frequency.
Abstract:
A flashlight comprising a high-pressure mercury vapor discharge lamp (1) (UHP lamp) is described. The miniaturized UHP lamp (1) enables flashlights with improved range due to the small electrode distance at high intensity in comparison to conventional HID lamps (mostly used in automotive lighting applications) as proposed by prior art. Additionally the application range is enlarged due to the smaller size of the high-end flashlight and the reduced requirements with respect to the driver circuitry.
Abstract:
A high-pressure mercury vapor discharge lamp (1) comprising an envelope (2) of high temperature resistant material having a discharge vessel (3) and two electrodes (5, 6) extending from two seal portions (4) into the discharge vessel (3), the two electrodes having an electrode gap (de) smaller than or equal to 2.5 mm, preferably smaller than or equal to 1.5 mm, is described. The discharge vessel (3) contains a filling which essentially comprises the following substances: rare gas, oxygen, halogen consisting of chlorine, bromine, iodine, or a mixture thereof, as well as mercury in a quantity greater than or equal to 0.15 mg/mm3' The seal portions (4) have a cross-sectional area of between 6 mm2 and 20 mm2, preferably approximately 10 mm2.A method of manufacturing such a high-pressure mercury vapor discharge lamp (1) and a projector system for such a high-pressure mercury vapor discharge lamp (1) are also described.
Abstract:
The present invention is directed to a laser resonator emitting visible ra diation with reduced speckle noise, wherein said optical resonator is formed by at least two mirrors (16a, 16b) at both ends of a visible radiation emitting lasing material, wherein that optical resonator enhances multimode operation, so that said visible radiation emitting lasing material emits a spectrally broadened visible radiation, wherein the enveloping function of said spectrally broadened visible radiation has a full width at half maximum (FWHW) within 1 nm to 15 nm.
Abstract:
The invention describes a method of shutting down a high pressure discharge lamp (1) in which a pair of electrodes (2) are disposed in an arc tube (3). This method comprises the steps of reducing the lamp power (PA) to a reduced operation level that enables the maintenance of an arc discharge between the electrodes (2) in a transition state from a lighting state to an extinguished state; driving the lamp (1) at the reduced operation level such that that the lamp (1) cools down; monitoring the lamp voltage (U) during this lamp power reduction process and during driving of the lamp (1) at the reduced operation level with regard to a defined discharge process stability criteria and increasing the lamp power (PA) if the discharge process stability criterion is not satisfied; completely shutting down the lamp power (PA) after sufficient duration to allow the lamp (1) to cool down to a state in which the gas pressure is such that the lamp (1) could be reignited shortly after being extinguished. Moreover the invention describes an appropriate driving unit (7) for driving a high pressure discharge lamp (1) and an image rendering system (40), particularly a projector system, comprising such a driving unit (4).
Abstract:
The invention relates to a lighting device comprising a lamp (1) comprising a burner (10) with an ionizable filling and an amount of mercury contained herein, having at least one mercury absorbing/adsorbing and/or blocking means (40) located outside the burner for the fixation of mercury in case of an explosion of the burner.