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: An optical sensing unit is provided which comprises at least one sample measurement cell, at least one excitation light source acting upon the or each measurement cell to provide one or more sensor fields defining an array of measurement fields, a photoelectric detector array for detecting the intensity of light emitted from the or each measurement cell in response to excitation light, and means for directing light emitted from each measurement field to a respective portion of the photoelectric detector array. The sensing unit may be used in combination with multiplexed waveguide arrays or multiplexed planar cappillary chromatography or electrophoresis chips.

Abstract: A method for generating quasi-sinusoidal signals includes illuminating an object capable of diffusely scattering light, focusing a portion of the scattered light on a multi-element sensor to form an image, and matching the image size to the size of the sensor elements.

Abstract: A method for generating quasi-sinusoidal signals includes illuminating an object capable of reflecting light, focusing a portion of the reflected light on a multi-element detector to form an image, and matching the image size to the size of the detector elements. A first weighted sum of signals generated by a first set of elements produces an in-phase signal, and a second weighted sum of signals generated by a second set of elements produces a quadrature signal. Weights are signed quantities selected to exhibit a band-pass behavior in the spatial frequency domain, thereby attenuating noise generated by, for example, non-uniform surface reflectance and non-uniform illumination.

Abstract: Apparatus for and a method of optical inspection in a total internal reflection holographic imaging system. Multi wavelength laser beams are directed onto a prism supporting a first substrate containing pre-recorded hologram which is to be imaged onto a recording medium of a second substrate, the multi wavelength beams being normal to both substrates. The distance between the two substrates is measured by interferometric techniques. Actuators are provided for adjusting the distance between the two substrates, these actuators being energized to cause minute adjustments of the spacing during a scanning operation whereby the imaging of the pre-recorded hologram is ensured at the correct focus throughout the scanning operation.

Abstract: An optical detection system particularly suited to us as a pointing device uses a photodetector array capable of generating a quasi-sinusoidal signal in response to illumination with an image of appropriate size. The detection system can use either coherent or non-coherent light, and existing textures in standard materials such as paper or printed patterns.

Abstract: A method for generating quasi-sinusoidal signals includes illuminating an object capable of diffusely scattering Eight, focusing a portion of the scattered light on a multi-element sensor to form an image, and matching the image size to the size of the sensor elements.

Abstract: Microlithography techniques have provided a means for the development of many useful devices from microcircuits, which made the computer era possible, to micromechanical devices such as motors that are only a few tens of microns across. A new use of a microdevice is presented here which serves to "payback" the art of microlithography as it is a significant contribution thereto. The device of the invention is a unique microdevice made with advanced microlithography techniques which when completed can be used as a new exposure tool for microlithography.A lens array can be as thin as 1/40 of the thickness of the page that this text is printed on, yet have thereon an arrangement of optical lenses powerful enough to replace very sophisticated and bulky, million dollar precision optics.An array of lenses can be fabricated with binary optical device and other techniques.

Abstract: The present invention discloses a method and an apparatus which enables one to obtain definite non-modulo-2.pi.-dependent measurements wherein a method for the fiber-optic measurement of force, which is based upon the strain-induced birefringence of a single-mode light waveguide, provides a compensation method for the phase differences of two linear modes of the exiting light waves, which are caused by the force acting on the light waveguide and the consequent change in birefringence. In one embodiment of the method, a liquid crystal cell, the birefringence effect of which can be controlled electrically, is used as a compensation element. The maximum of an autocorrelation function, which occurs as an image, and the respective voltage at the liquid crystal cell, are evaluated as a measurement for the birefringence which is to be compensated for and, accordingly, for the effective force.

Abstract: A method and the device for fiber-optic measurement of the absolute value of the pretensioning in a highly loaded mechanical structural component part are based on the measurement of the phase displacement of a light wave caused by the strain-induced birefringence in a single-mode light waveguide 4 which is embedded between two metallic disks or washers 3a, 3b. Since the measurement results are ambiguous modulo-2.pi., serial or simultaneous measurement with two light wavelengths .lambda..sub.1, .lambda..sub.2 is used according to a first method variant of the invention. The quantity of 2.pi. periods can be unequivocally determined within a predetermined measuring range by means of comparing the two measurement results. The evaluation is preferably effected according to a quadrature or phase step method, known per se. According to second method variant, the light waveguide 4 is irradiated with polarized white light.

Abstract: An apparatus for measuring changes in a variable interference section of an interferometer comprises a laser source for producing beams of the frequency n.sub.1 and the frequency n.sub.2, polarizing beam splitters for producing cross-polarized partial beams of frequency n.sub.1 or n.sub.2, modulators for displacing the frequency of one of the partial beams by frequency f.sub.1 or f.sub.2, a pair of deflecting mirrors in each case and polarizing beam splitters for combining the partial beam n.sub.1, n.sub.1 +f.sub.1, n.sub.2, n.sub.2 +f.sub.2. The apparatus further includes two photodetectors, upstream of which are arranged a polarizer, a Michelson interferometer, a non-polarizing beam splitter for splitting the partial beams in each case into a measuring light beam or a reference light beam. The reference light beam passes to an associated photodetector. The measuring light beam passes into the Michelson interferometer and then to the associated photodetector.

Abstract: The method comprises producing a coherent light beam in which the distribution of luminous intensity is representative of the object under study, forming an image representing the complex Fourier spectrum of the function describing said distribution of luminous intensity, and producing first data in response to the luminous intensity in a part of said image and second data in response to the relative phase of the light waves producing said image. The first data are representative of the object and of its orientation and the second data are representative of the position of the object.

Abstract: A method and apparatus for mutually adjusting the positioning of planar, generally transparent components such as for example, small liquid-crystal plates. The plates are provided with marks specially structured to diffract incident collimated light, in a shape or direction which is characteristic for each plate. By means of a convergent lens, characteristic diffraction images produced by passing light through the marks are depicted on a detector located in the image plane of the convergent lens. The respective characteristic images of the marks are stopped down individually by means of a diaphragm located in the lens focal plane. The diaphragm can periodically be closed partially, so that control signals for the electronic displacement of each plate can be derived individually from the particular positions of the images of the marks on the detector, corresponding to the positions of the plates.

Abstract: A method and apparatus for adjusting the relative positioning of planar transparent objects, such as the two glass plates of a liquid crystal display, (LCD). Textured transparent markings are disposed on the planar transparent objects. Thereafter a collimated light beam is passed through the transparent textured markings and refracted thereby. Images of the textured markings are observed and detected, whereupon the relative positioning of the planar transparent objects is adjusted until the detected images are aligned in a predetermined spatial orientation. Also disclosed is a novel liquid crystal display having the transparent textured markings provided on the transparent electrode layers of the LCD device.