Abstract: An electro-optic detector for detecting terahertz radiation comprising an electro-optic material through which the terahertz radiation passes; a probe for transmitting probe radiation into the electro-optic material; an optical arrangement for causing the probe radiation to make multiple passes through the electro-optic material and a radiation detector for detecting the probe radiation after the multiple passes are made.

Abstract: An electro-optic detector for detecting terahertz radiation comprising an electro-optic material through which the terahertz radiation passes; a probe for transmitting probe radiation into the electro-optic material; an optical arrangement for causing the probe radiation to make multiple passes through the electro-optic material and a radiation detector for detecting the probe radiation after the multiple passes are made.

Abstract: An optical device comprising a sealed waterproof housing comprising at least one LED disposed within the housing; a transparent window to allow light from the LED to be emitted from the housing; a non-imaging light element for coupling light from the LED into a plurality of side emitting optical fibers connected to the housing; and a fixing portion for securing the plurality of side-emitting optical fibers into a coupling position adjacent to the window to allow light to pass between the housing and the plurality of optical fibers, via the transparent window. The fixing portion is adapted to allow connection and/or disconnection of the plurality of optical fibers without opening or breaking a seal of the sealed waterproof housing.

Abstract: A communications system comprising at least one light source, a side-emitting fiber light rope into which light emitted from the light source is coupled, and means for sending at least one data carrying optical signal along the light rope.

Abstract: An optical parametric device comprising a slant-stripe periodically poled nonlinear material that is operable to generate signal in response to interaction with a pump wave, the non-linear interaction being such that the pump and idler waves are collinear and the signal wave is non-collinear relative to the pump and idler waves, wherein the slant-stripe non-linear material is able to generate two idler waves and two signal waves, and the device is adapted to allow for the selection and output coupling of a required one of the two signal waves.

Abstract: A method of optimizing parametric gain in a nonlinear optical crystal that in response to application of a pump beam generates through a parametric generation process signal and idler beams, wherein the signal beam is non-collinear with the pump beam and the signal beam is subject to absorption due to the nonlinear material, the method involving shaping the pump beam to have an elliptical cross section, wherein the method further involves determining the width w of the pump beam depending on the absorption co-efficient of the optical crystal.

Abstract: An optical device comprising a sealed/closed housing; a light source and/or a detector within the housing; a window through the housing that is transparent to light transmitted from the light source or to the detector and a fixing for fixing an optical fiber or bundle of such fibers into a coupling position adjacent to the window to allow light to pass between the housing and the fiber or fiber bundle, wherein the fixing is adapted to allow connection and/or disconnection of the fiber or fiber bundle without opening or breaking a seal of the sealed housing.

Abstract: An umbilical comprising a side-emitting optical fiber or optical fiber-bundle for providing a distributed source of light along part or the whole of the length of the umbilical.

Abstract: A method of optimizing parametric gain in a nonlinear optical crystal that in response to application of a pump beam generates through a parametric generation process signal and idler beams, wherein the signal beam is non-collinear with the pump beam and the signal beam is subject to absorption due to the nonlinear material, the method involving shaping the pump beam to have an elliptical cross section, wherein the method further involves determining the width w of the pump beam depending on the absorption co-efficient of the optical crystal.

Abstract: An optical parametric device comprising a slant-stripe periodically poled nonlinear material that is operable to generate signal in response to interaction with a pump wave, the non-linear interaction being such that the pump and idler waves are collinear and the signal wave is non-collinear relative to the pump and idler waves, wherein the slant-stripe non-linear material is able to generate two idler waves and two signal waves, and the device is adapted to allow for the selection and output coupling of a required one of the two signal waves.

Abstract: An optical device comprising a sealed/closed housing; a light source and/or a detector within the housing; a window through the housing that is transparent to light transmitted from the light source or to the detector and a fixing for fixing an optical fiber or bundle of such fibers into a coupling position adjacent to the window to allow light to pass between the housing and the fiber or fiber bundle, wherein the fixing is adapted to allow connection and/or disconnection of the fiber or fiber bundle without opening or breaking a seal of the sealed housing.

Abstract: A lighting system comprising a light source, a fiber rope into which light emitted from the light source is coupled, and a control unit for controlling the optical power of light emitted by the light source to maintain the fiber rope at or below a predetermined upper temperature even if the fiber is partially or fully severed.

Abstract: A communications system comprising at least one light source, a side-emitting fiber light rope into which light emitted from the light source is coupled, and means for sending at least one data carrying optical signal along the light rope.

Abstract: An umbilical comprising a side-emitting optical fiber or optical fiber-bundle for providing a distributed source of light along part or the whole of the length of the umbilical.

Abstract: An intra-cavity optical parametric oscillator. The oscillator includes means for providing a non-linear loss for suppressing relaxation oscillations.

Abstract: A lighting system comprising a light source, a fiber rope into which light emitted from the light source is coupled, and a control unit for controlling the optical power of light emitted by the light source to maintain the fiber rope at or below a predetermined upper temperature even if the fiber is partially or fully severed.

Abstract: An all-solid-state laser comprising a slab (1) of gain medium, a diode laser pump system (3) configured in an end pumping geometry with the gain medium (1) and a heat sink thermally contacted to the gain medium (1) wherein the diode laser pump system (3) and the gain medium (1) are cooperably arranged so that in use a positive thermal lens is capable of being formed within the medium, the gain medium (1) having a thickness (d-d') made as small as possible while permitting the substantially unhindered passage through the slab of the laser mode established between the two mirrors (M1, M2).