Abstract: The invention relates to a rain sensor, especially for a motor vehicle, said sensor comprising an optical waveguide (22) which can be arranged in a windscreen. According to the invention, the planar holographic coupling elements for coupling and decoupling radiation (4) are formed from layered photo-polymer parts (3) into which volume holograms are integrated. The photo-polymer parts (3) are arranged between the core (1) of the waveguide and the envelope of the waveguide (2), resulting in a simple production method and an increased flexibility in terms of the arrangement of the waveguide (22) in the windscreen.

Abstract: In an optical sensor for detecting moisture on a windshield of a motor vehicle, in which the light radiation is deflectable to a detection area on the windshield situated in the light path between transmitter and receiver, the transmitter and/or the receiver have a transparent design and are integrated into the windshield. The transparent optical elements may thus be situated in the area of a wiped field of the windshield cleaned by the windshield wiper.

Abstract: A high-resolution fiber laser sensor for measuring a quantity to be measured M has a pumping light source, a fiber laser and a detection/evaluating unit. The fiber laser has: a birefringent first end reflector, a second end reflector, a laser-amplifying fiber, a sensor fiber and a mode coupling. The laser-amplifying fiber, the sensor fiber and the mode coupling are arranged between the end reflectors. In the fiber laser, light is capable of propagating in two optical states which are orthogonal to one another due to their polarization and/or their transversal space structure. The orthogonal optical states can be coupled to one another by the mode coupling. In the fiber laser, a number of longitudinal modes are capable of oscillating in each of the two optical states. In the sensor fiber a change in the birefringence for the two orthogonal optical states can be achieved by interaction of the quantity to be measured with the sensor fiber.

Abstract: A high-resolution fiber laser sensor for measuring a quantity to be measured M has a pumping light source (2), a fiber laser (1) and a detection/evaluating unit (3). The fiber laser (1) has: a birefringent first end reflector (11), a second end reflector (12), a laser-amplifying fiber (13), a sensor fiber (14) and a means for mode coupling (15). The laser-amplifying fiber (13), the sensor fiber (14) and the means for mode coupling (15) are arranged between the end reflectors (11, 12). In the fiber laser (1), light is capable of propagating in two optical states (x, y; LP?01, LP?11) which are orthogonal to one another due to their polarization and/or their transversal space structure. The orthogonal optical states (x, y; LP?01, LP?11) can be coupled to one another by the means for mode coupling (15). In the fiber laser (1), a number of longitudinal modes (LMxp, LMxp+1 . . . , LMyq, LMyq+1 . . . ; LM01p, LM01p+1 . . . , LM11q, LM11q+1 . . .

Abstract: A fiber laser sensor has a fiber laser (FL) with two reflectors in the form of a first and a second Bragg grating (4, 5) and a fiber segment (3) arranged in between. The first Bragg grating (4) is arranged in a temperature-sensitive fashion. The second Bragg grating is a chirped Bragg grating (5) whose central wavelength is stabilized with regard to temperature changes. By means of this sensor, temperature and pressure can simultaneously be measured separately from one another, beat frequencies of orthogonal polarization eigenmodes of the fiber laser (FL) being a measure of the pressure and beat frequencies of longitudinal modes being a measure of the temperature.

Abstract: A fiber laser sensor has a fiber laser (FL) with two reflectors in the form of a first and a second Bragg grating (4, 5) and a fiber segment (3) arranged in between. The first Bragg grating (4) is arranged in a temperature-sensitive fashion. The second Bragg grating is a chirped Bragg grating (5) whose central wavelength is stabilized with regard to temperature changes. By means of this sensor, temperature and pressure can simultaneously be measured separately from one another, beat frequencies of orthogonal polarization eigenmodes of the fiber laser (FL) being a measure of the pressure and beat frequencies of longitudinal modes being a measure of the temperature.

Abstract: The instant invention relates to a method and an arrangement for the space-based operation of quantum-optical amplifiers embodied as optical waveguides, while taking the special conditions to be found in space into consideration. An amplifier housing 2 filled with nitrogen has a cutout into which a plan-parallel quartz glass plate 4 has been fitted, through which light beams can enter and leave the housing. The amplifier housing 2 rests on heat-insulating supports 3a, 3b and is temperature-stabilized by a Peltier element 5. The amplifier housing 2 is filled with nitrogen in order to achieve operating conditions similar to those on earth.