Abstract: The invention relates to the field of laser sources (3), and for specifically to inhibiting damage due to misuse of a laser source (3), in particular of a high-power laser source (3) provided in a consumer product (1). The proposed device (1) includes at least a laser source (3) and a safety unit (2), wherein by means of the arrangement of the safety unit (2) it is provided that potential harm caused by misuse of the laser source (3) based on an unauthorized access to the laser source (3) is confined or even prevented by reducing the power level of the output of the laser source (3) or by even completely stopping any laser output therefrom. A corresponding method of providing a laser source (3) and a further method of preventing misuse of a laser source (3) are also proposed.

Abstract: The invention relates to a method of making Ce3+ containing laser materials with a fast cooling rate.

Abstract: A method 200 of manufacturing a (part of) color ring is provided. The color ring converts a color of light emitted by a light emitter into at least one other color. The method (200) comprising the steps of: i) pressing (102) a first ring body of a first granulated precursor comprising a first luminescent material for converting the color of the light of the light emitter into a first one of the at least one other color, and ii) sintering (104) the first ring body for obtaining a first ceramic ring. The color ring comprises at least a segment of the first ceramic ring.

Abstract: The invention relates to a ceramic non-cubic fluoride laser material and methods of its manufacture.

Abstract: The invention relates to a lighting apparatus for generating light. A primary light generator generates primary light (6), which is converted by a light converting material (8) into secondary light (3), wherein the primary light is directed to a primary surface (9) of the light converting material. An enclosure (10) comprising a transparent cover (7) hermetically encloses the light converting material, wherein the transparent cover is transparent to the primary light and located on the primary surface of the light converting material. The enclosure increases the photostability of the light converting material. This allows increasing the intensity of the primary light by, for example, increasing the power of the primary light and, thus,of the secondary light, and/or by focusing the primary light onto a smaller area on the primary surface, thereby allowing decreasing the optical Étendue of the secondary light, without damaging the light converting material.

Abstract: The invention relates to a laser (1) for emitting laser light in the visible spectral range. A rare earth doped anisotropic crystal (2) comprising a 5d-4f transition is arranged within a laser resonator (7, 8), and a pumping light source (3) pumps the crystal (2) for generating laser light in the visible spectral range by using the 5d-4f transition. The 5d-4f transition of the rare earth doped anisotropic crystal comprises an absorption band extending over several nm. Thus, pump light having a wavelength within a relatively broad wavelength range can be used. This reduces the requirements with respect to the wavelength accuracy of the pumping light source and, thus, more pumping light sources of an amount of produced pumping light sources can be used for assembling the laser, thereby reducing the amount of rejects.

Abstract: The present invention relates to a switchable dual wavelength solid state laser with a solid state gain medium (1) which is selected to emit optical radiation at a first wavelength with a first polarization and of at least a second wavelength with a second polarization different from said first polarization when optically or electrically pumped. A polarizing device (7) is arranged within the laser cavity, said polarizing device (7) being adjustable at least between said first and said second polarization. The two end mirrors (2, 3) of the laser cavity are designed to allow lasing of the solid state laser at the first wavelength when the polarizing device (7) is adjusted to the first polarization, and to allow lasing of the solid state laser at the second wavelength when the polarizing device (7) is adjusted to the second polarization. The proposed solid state laser allows an easy switching between two emission wavelengths.

Abstract: The invention describes a heating system (13) for heating a body (1) of a preform having a material thickness bounded by a first surface (2) and a second surface (4). The heating system (13) comprises at least a light source arrangement (12) which is arranged to emit a number of directed light beams (17) and a coupling arrangement (15, 21) realized to deliberately couple light from the light source arrangement (12) in a specific direction into the body (1) during at least a certain minimum period such that the light is essentially guided along a longer path (19) between the first (2) and second surface (4). Furthermore, the invention concerns a method of heating a body (1) of a preform.

Abstract: The present invention relates to a switchable dual wavelength solid state laser with a solid state gain medium (1) which is selected to emit optical radiation at a first wavelength with a first polarization and of at least a second wavelength with a second polarization different from said first polarization when optically or electrically pumped. A polarizing device (7) is arranged within the laser cavity, said polarizing device (7) being adjustable at least between said first and said second polarization. The two end mirrors (2, 3) of the laser cavity are designed to allow lasing of the solid state laser at the first wavelength when the polarizing device (7) is adjusted to the first polarization, and to allow lasing of the solid state laser at the second wavelength when the polarizing device (7) is adjusted to the second polarization. The proposed solid state laser allows an easy switching between two emission wavelengths.

Abstract: A laser projection system includes at least one laser light source, a projection screen and a spatial light modulator for projecting a laser beam of the laser light source to form an image on the projection screen. The projection screen includes a luminescent layer which upon excitation by the laser beam emits blue light. The luminescent layer contains MSi6?aAlaN8?aOx+a:Eu2+ (with M=Sr, Ba,; 0?x?1; 0?a?1) as a luminescent material. With this material laser light of a laser diode emitting in the wavelength region of 405 nm can be converted to blue light of 450 nm with high efficiency. The proposed projection system, therefore, is suitable for RGB projection using laser diodes as laser light sources.

Abstract: The invention relates to a light emitting device (1) with high colour rendering comprising a wavelength converting member (2) with a luminescent medium for wavelength conversion of blue light and/or ultraviolet light (10) into red light and/or yellow and/or green light and a light source (3) emitting blue light (10) and/or ultraviolet light arranged to pump the luminescent medium, said luminescent medium essentially having a main phase of a solid state host material which is doped with Ce3+-ions. According to the invention the host material comprises ions of a further rare-earth material Ln, wherein the host material is selected such that the emission energy of the 5d-4f emission on Ce3+-ions is energetically higher than the absorption energy into an upper 4fn state of the further rare-earth material Ln, and wherein the light emission of wavelength converted light is caused by an intra-atomic 4fn-4fn transition within the ions of the further rare-earth material.

Abstract: For a diode pumped solid-state laser, measures to improve the pump light absorption in anisotropic crystals are proposed. The proposed measures reduce the dependency of the pump light absorption on the diode current and the diode temperature as well as on the detuning of the pump diode from the absorption line. These measures include sending the pump radiation twice through the crystal, placement of the laser crystal in an orientation that does not exhibit the optimum absorption and the use of a retarder.

Abstract: The invention relates to a solid-state laser device (1) comprising a gain medium (10) essentially having a main phase of a solid state host material (15) which is doped with rare-earth ions.

Abstract: The invention relates to an apparatus (1) for determining a flow property of a fluid (2). The apparatus comprises a distance and velocity determination unit (3) for determining distances of elements of the fluid to the distance and velocity determination unit (3) and for determining velocities of the elements at the same time based on a self-mixing interference signal. The apparatus (1) comprises further a flow determination unit (4) for determining the flow property of the fluid (2) based on at least one of the determined distances and velocities. This allows determining the flow property, even if the fluid (2) is optically thick.

Abstract: The present invention relates to a method of switching laser emission of a solid state laser between different emission wavelengths, said different emission wavelengths being based on different electronic transitions in a solid state laser medium (3) of the solid state laser. The at least two end mirrors (1, 2) of the solid state laser are designed to allow lasing of the laser at the different emission wavelengths and coupling out of the different emission wavelengths at one end mirror (2) of the laser cavity. The switching of the laser emission is achieved by switching the cavity length of the laser cavity between different cavity lengths, wherein the different cavity lengths are selected such that at each of the cavity lengths the solid state laser lases at only one of the different emission wavelengths which is different from the emission wavelengths at the other of the selected cavity lengths.

Abstract: The present invention relates to a solid state laser device with a solid state gain medium between two resonator end mirrors (3, 5) and a GaN-based pump laser (1) arranged to optically pump the solid state gain medium. The solid state gain medium is a Pr3+-doped crystalline or polycrystalline host material (4) which has a cubic crystalline structure and highest phonon energies of ?600 cm?1 and provides a band gap of ?5.5 eV. The proposed solid state laser can be designed to emit at several visible wavelengths with the emitted power showing a reduced dependence on the temperature of the GaN-based pump laser (1).

Abstract: It is an object of the invention to provide a simple setup of a waveguide laser which allows to control the emission of specific laser wavelengths in a laser material having laser transitions of similar wavelengths. For this purpose a core (4) forming a gain medium is provided with a cladding (6) which introduces losses to an undesired laser transition but is transparent to the light of a desired laser transition. A second cladding (8) is provided for guiding the laser radiation. Pr: ZBLAN with a Tb: doped cladding may be used. Instead of the absorbing cladding (6) a photonic crystal (20) may be used. The laser is end-pumped by a laser diode (14).

Abstract: An optical sensor (600) for detecting the movement of an object relative to the position of the optical sensor (600), using self-mixing interference, is described. The optical sensor (600) comprises a laser (100), a detector (200) and a filter device (500). The filter device (500) suppresses measurement signals generated by means of the detector (200) when movements of the object at a velocity below a defined threshold value cause the measurement signals. The optical sensor (600) may be used in a switch in order to enable selective switching depending on the velocity of the movement of the object.

Abstract: The present invention provides an intracavity frequency-converted solid state laser for the visible wavelength region. The laser comprises a semiconductor laser (1) with an extended laser cavity (2). A second laser cavity (4) is formed inside of said extended laser cavity (2). The second laser cavity (4) comprises a gain medium (3) absorbing radiation of the semiconductor laser (1) and emitting radiation at a higher wavelength in the visible wavelength region. The frequency converting gain medium (3) is formed of a rare-earth doped solid state host material. The proposed laser can be manufactured in a highly integrated manner for generating radiation in the visible wavelength region, for example in the green, red or blue wavelength region.

Abstract: The present invention relates to a solid-state laser comprising a gain medium (6) of a solid-state host material which is co-doped with Ce3+-ions and ions of a further rare-earth material. The host material is selected such that a lower edge of the 5d band of the Ce3+-ions is energetically higher than an upper lasing state of the ions of the further rare-earth material. This laser can be optically pumped by GaN laser diodes (4) in the wavelength region between 400 and 450 nm and emits laser radiation in the visible wavelength range. With this laser, in particular, a GaN diode laser pumped solid-state laser emitting in the green wavelength region can be realized.