Abstract: The invention includes a deformable mirror for use in adaptive and active optical systems and in optical technology laser communication directed energy systems. The invention utilizes pockets formed in the back of the mirrors substrate. The pockets house actuators that are bonded to the substrate and may adjustably deform the mirror surface depending on the voltage supplied to the actuators. A plurality of mirrors may be combined to form a scalable array or positioned to overcome issues related to the uncontrollable portions of separate individual mirrors.

Abstract: A method and a device for reducing speckle formation on a projection display when working with a coherent light source. In this context, the light coming from the light source, before the projection, may strike an electrically controllable optical element having a spatially inhomogeneous refractive index, passing through the same, the refractive index being varied over time within the projection period. This may lead to an averaging out of the speckle pattern on the projection screen. For purposes of illumination, a multimode light source may be used, and/or the light coming from the light source is separated into a plurality of spatial modes, thereby reinforcing the effect. As an optical element, one may employ a liquid crystal element composed of at least two liquid crystal layers, to which a spatially dependent voltage is applied to generate a spatially dependent refractive index. Its birefringence may be compensated by orientating the layers to one another in appropriate fashion.

Abstract: A device for generating, adding and subtracting digital sequences of optical pulses and a method for the secure transmission of information. An interferometer having at least one electro-optical switch or electro-optical modulator positioned in one of its branch sections is used so that binary optical pulse sequences may be added and/or subtracted in the context of an electro-optical device and a method for the secure transmission of information using optical signals.

Abstract: An intensity-dependent light modulating device and method involves light successively passing through a polarizer, a first phase retardation plate and a first light modulator. The light then strikes a mirror and then passes once again through the light modulator and the phase retardation plate in the opposite direction, and then strikes an analyzer that is crossed relative to the polarizer. The light modulator and the phase retardation plate are respectively located in an electric field in which the indicatrices of the light modulator and the phase retardation plate are deflected, wherein the deflection of the indicatrix of the light modulator is intensity-dependent. Due to the passage of light through the phase retardation plate and the light modulator, an intensity-dependent rotation of the direction of polarization occurs in such a way that higher intensity light is filtered in the analyzer while lower intensity light is transmitted.

Abstract: An intensity-dependent light modulating device or method for providing same, involves light successively passing through a polarizer, a first phase retardation plate and a first light modulator. The light then strikes a mirror and from there on, it passes once again through the light modulator and the phase retardation plate in the opposite direction and then strikes an analyzer that is crossed relative to the polarizer. The light modulator and the phase retardation plate are respectively located in an electric field in which the indicatrices of the light modulator and the phase retardation plate are deflected, wherein the deflection of the indicatrix of the light modulator is intensity-dependent. Due to the passage of light through the phase retardation plate and the light modulator, an intensity-dependent rotation of the direction of polarization occurs in such a way that higher intensity light is filtered in the analyzer while lower intensity light is transmitted.

Abstract: An intensity-dependent light modulating device involves a light successively passing through a polarizer, a first phase retardation plate and a first light modulator. The light then strikes a mirror and passes one again through the light modulator and the phase retardation plate in the opposite direction. The light then strikes an analyzer that is crossed relative to the polarizer. The light modulator and the phase retardation plate are respectively located in an electric field in which the indicatrices of the light modulator and the phase retardation plate are deflected, the deflection of the indicatrix of the light modulator being intensity-dependent. Due to the passage of light through the phase retardation plate and the light modulator, an intensity-dependent rotation of the direction of polarization occurs in such a way that higher intensity light is filtered in the analyzer while lower intensity light is transmitted.

Abstract: The present invention relates to a method and a device for forming the intensity profile of a laser beam, in particular for producing a homogeneous intensity profile. In an embodiment of the present invention, the laser beam can strike an optically addressable spatial light-modular (OASLM), whose local transmission or reflection properties depend in nonlinear fashion on the local illumination intensity.

Abstract: To provide a phase modulator for introducing a topological phase, which is designed to produce any desired phase shift between zero and 360°, the phase modulator has means, at least one double-refractive, electrooptical delay element having a rotatable indicatrix, which is/are used to direct the polarization of the light, during transmission through the modulator, over at the light one closed path on the Poincaré sphere, the indicatrix rotating in accordance with the predefined phase shift, and the total encircled surface on Poincaré sphere being equal in terms of absolute value to ?.

Abstract: An electrically drivable light modulator having liquid crystal layers, which are disposed one behind the other and are enclosed between transparent plates having a surface anisotropy that orients the molecules of the liquid crystals and having electrodes for generating an electric field in the liquid crystals, at least two layers of helical, smectic, ferroelectric liquid crystals are situated one behind the other in the path of rays of a light beam to be modulated. The directions of the fast and slow axes of the individual layers are rotated relatively to each other so that the polarization of the light beam is the same upstream and downstream from the modulator. An adaptive, optical device has a field of light modulators configured in a raster-type array, in which the modulators are situated in the path of rays of the device, each individual light modulator being able to be driven to compensate for unsharpness occurring on a point-by-point basis in an image to be processed.

Abstract: The invention relates to an intensity-dependent light modulating device, wherein said light successively passes through a polarizer, a first phase retardation plate and a first light modulator; the light then strikes a mirror and from there on, it passes once again through the light modulator and the phase retardation plate in the opposite direction and then strikes an analyzer that is crossed relative to the polarizer. The light modulator and the phase retardation plate are respectively located in an electric field in which the indicatrices of the light modulator and the phase retardation plate are deflected, wherein the deflection of the indicatrix of the light modulator is intensity-dependent. Due to the passage of light through the phase retardation plate and the light modulator, an intensity-dependent rotation of the direction of polarization occurs in such a way that higher intensity light is filtered in the analyzer while lower intensity light is transmitted.

Abstract: A quantum cryptography system using electrooptical liquid crystal modulators which change the polarization and which are designed as electrically rotatable retardation plates whose two birefringent axes are rotated by the applied electrical field around an angle &thgr; which depends on the strength of this field. A &lgr;/2 retardation plate rotates the elliptically polarized light striking the plate around an angle 2&thgr; at speeds in the microsecond range. The quantum cryptography system can be used for interception-proof data transmission over transmission links that are accessible to the public.

Abstract: A liquid crystal display cell comprising a chiral ferroelectric smectic liquid crystal layer whose helix structure is influenced by the action of an electric field such that its optical anisotropy alters; a pair of transparent plates between which the liquid crystal is disposed and which have a surface structure for aligning the molecule of the liquid crystal and are provided with electrodes to produce an electric field therein; and one polarizer each before and after the liquid crystal, such that a ratio d/p of the thickness d of the liquid crystal layer to the pitch height p of the helical twisting is greater than 5, the smectic tilt angle &thgr;o between 0.39 radians and 0.87 radians and the product d·&thgr;2·&Dgr;n·1/&lgr; (phase factor) of the thickness d, the square of the tilt angle &thgr;°, the value of the birefringence &Dgr;n and the reciprocal of the wavelength &lgr; of light bending is greater than 0.45 radians2.

Abstract: A liquid crystalline material having a lamellar structure can be used for phase modulation. A liquid crystal having arcuated or angular dimer molecules so that the molecules each include two central units, and the longitudinal axes of the two central units exhibit at least approximately oppositely directed inclination angles with respect to the layer normal z. By configuring the two central units of the dimer molecule in accordance with the present invention, the molecular index ellipsoid, which is essentially composed of the components of the two readily polarizable central units, may be positioned such that the optical axis is always situated in parallel to the layer normal z, making it possible to prevent the light, which propagates in a defined direction orthogonally to the layer normal through the liquid crystalline material, from undergoing a polarization modulation simultaneously with the phase modulation.

Abstract: A device for the local attenuation of the light intensity in the field of vision of a light-sensitive monitoring and/or recording device (CCD) is described, which is suitable in particular as a glare protection device for video cameras in videophones or correspondingly equipped PCs. The device includes a first objective (L1) and a high resolution ferroelectric liquid crystal modulator (PC, LC) arranged between two polarizers (P1, P2), the liquid crystal modulator having a photo-conductive layer (PC) and a downstream liquid crystal film (LC) made up of helical smectic liquid crystals which is in contact with this layer. The photo-conductive layer (PC) is essentially arranged in the image plane of the first objective (L1), the image plane being imaged onto the monitoring and/or recording device by a second objective (L2). As this occurs, bright light sources or backgrounds are locally suppressed without resulting in a glare or bloom of the image.

Abstract: In order for binary optical pulse sequences to be able to be added and/or subtracted in the context of an electro-optical device and a method for the secure transmission of information using optical signals, an interferometer is used, which has at least one electro-optical switch or modulator positioned in one of its branch sections.

Abstract: WDM multi-channel systems for large distances having a number of intensifiers may cause an increase in intensifications, which lead to considerable differences in intensity, even given modest wavelength dependence, making spectral leveling maybe necessary. The light from the fiber is first spectrally into channels, and, thus locally separated, projected onto the surface of an optic limiter based on an OASLM (optical addressed, spatial light modulator), in which the intensive channels are overproportionally attenuated. The tension dependence of liquid crystal cells, derived from exposure, is used to level the WDM channels. Lastly, the channels are again imaged onto a point and coupled into another fiber. The invention is used in WDM multi-channel systems for large distances a number of intensifiers.

Abstract: WDB multi-channel systems for large distances having a number of intensifiers cause an increase in intensification, which can lead to considerable differences in intensity, even given modest wavelength dependence This makes spectral levelling necessary. In accordance with the invention, the light from the fiber is first split spectrally into channels, and, thus locally separated, projected onto the surface of an optic limiter based on an OASLM (optical addressed, spatial light modulator), in which the intensive channels are overproportionally attenuated The tension dependence of liquid crystal cells, derived from exposure, is used to level the WDM channels Lastly, the channels are again imaged onto a point and coupled into another fiber.

Abstract: A method for applying a light-blocking layer between a photoconducting layer and a mirror when making an optically addressable spatial light modulator (OASLM) using a chemical vapor deposition process. The light-blocking layer and the photoconducting layer are applied in a shared process step in which both the thickness and composition of the photoconducting layer to be applied to the transparent electrode, as well as the thickness and composition of the light-blocking layer to be applied to the photoconducting layer are determined by a time-related change of the variation of the gas composition during the deposition process. The structure of the OASLM can be optimally adapted to a desired purpose.

Abstract: In an arrangement and a method for electrically controlling the intensity of non-polarized light, a polarizing beam splitter is acted upon by the light to be controlled via an input face such that the light is split into two polarized light bundles that are orthogonal with respect to each other. Provision is made that a first reflecting device is configured for the reflection of at least one of the polarized light bundles, so that both polarized light bundles run in parallel. At least one electro-optical element is provided in a path of the parallel running polarized light bundles. The polarization is changed as a function of the supplied control voltage. Also provided is a second reflecting device for reflecting the light bundles in the opposite direction.

Abstract: A method and a device are described to compensate for polarization mode dispersion in an optical transmission link(9, 9′) having polarization-dependent transmission characteristics, in particular in optical fibers and cables with not only statistical, but preferred birefringence. A compensation element (1, 1′, 1″), whose length is adjusted non-destructively using an interference device (2, 2′, 2″), in particular a pressure mechanism, is connected upstream or downstream from the transmission link (9, 9′). The polarization states PL and PS of the compensation element are mixed by the interference and thus the length of the compensation fiber is defined at which a propagation time difference between the partial waves of polarization states PL and PS is increased or decreased so that it compensates for the propagation time difference &tgr; within the transmission link (9, 9′).