Abstract: A groove is formed in a substrate layer by ion etching. The substrate layer comprises a top layer having an etch rate S1 and a bottom layer having a different etch rate S2, in which first, grooves are formed having an initial depth which differs from the desired depth, after which the etching process is carried out without using a mask until the desired depth of the groove is attained.

Abstract: The invention relates to a planar optical isolator having a magneto optical gyrotropic layer and an anisotropic birefringent layer which are proportioned so that the non-reciprocal rotation of polarisation of the light (Faraday rotation) resulting from the action of a magnetic field in the forward direction of the isolator is at least substantially negatively equal to the reciprocal rotation of polarisation as a result of the birefringence, so that a TE-mode in the forward direction is guided with low damping, measures being taken for the intensive attenuation of at least one TM-mode. An isolator having a high isolating effect in which magneto optical gyrotropic layers and anisotropic birefringent layers can be connected epitaxially is obtained in that the waveguiding core layer comprises two rare earth-iron garnet (YIG) layers which are differently doped to obtain different specific birefringence.

Abstract: A device for working a workpiece by means of laser light includes a laser, a beamsplitter for splitting the laserbeam into at least two sub-laserbeams of substantially identical intensities, and a control unit which controls the light intensity of the laser and the movement of a workpiece support and the laserbeam relative to each other. The beamsplitter includes at least one digital-phase grating which divides the laserbeam into a plurality of sub-laserbeams to produce a pattern of laser spots onto the workpiece.

Abstract: A magneto-optical waveguide device for changing the radiation modes propagating in the structure comprises a magneto-optical layer in which the modes propagate and which is externally magnetized. This magneto-optical layer is carried by a substrate and is connected to an optically anisotropic structure. This optically anisotropic structure is an artificially formed phase structure having zones of different refractive indices, the zones and their distances from each other in the direction of propagation of the modes being small relative to the wavelength of the light.

Abstract: The invention relates to an optical wavelength multiplexing and/or demultiplexing device. The device comprises a digital phase grating having at least four steps. The grating diffracts light of at least three different wavelengths in different central diffraction orders. Since the grating period may be high in comparison with the wavelengths light-emitting diodes may be used as light sources.

Abstract: The invention relates to a compound blazed optical phase grating. The grating comprises at least two grating sections which are disposed opposite each other in parallel planes. The gratings have grooves which extend parallel to each other. The grating sections have equal grating periods and are movable relative to each other within their planes and perpendicular to the grooves. Over one grating period, the optical path length varies at least substantially parabolically and symmetrically relative to the grating period. The path length varies in such a manner that when both grating sections are symmetrically arranged relative to a common line perpendicular to the grating planes, the optical path length through the compound grating is uniform across the grating. Various optical switches and switching matrixes can be formed by using such compound phase gratings.

Abstract: An optical power divider for use with one incoming and a plurality of outgoing glass fibers includes an imaging device arranged on an optical axis between the incoming and outgoing glass fibers. At least one plane binary phase grating is disposed in the pupil of the imaging device. The grating is one-dimensional, has a duty factor of at least substantially 1:1, and has an optical path difference of at least substantiallyH=0.32.lambda.+n.lambda.or H'=0.5.lambda.+n.lambda.where n=0,1,2 . . . . The end of the incoming glass fiber is coaxial with the optical axis. The outgoing glass fibers are arranged in such a way that they receive the radiation which has been diffracted into the various diffraction orders of the phase grating. .lambda. is the wavelength of the radiation.

Abstract: The invention relates to a compound blazed optical phase grating. The grating comprises at least two grating sections which are disposed opposite each other in parallel planes. The gratings have grooves which extend parallel to each other. The grating sections have equal grating periods and are movable relative to each other within their planes and perpendicular to the grooves. Over one grating period, the optical path length varies at least substantially parabolically and symmetrically relative to the grating period. The path length varies in such a manner that when both grating sections are symmetrically arranged relative to a common line perpendicular to the grating planes, the optical path length through the compound grating is uniform across the grating. Various optical switches and switching matrixes can be formed by using such compound phase gratings.

Abstract: A device for coupling a first optical signal of a first wavelength into a transmission glass-fiber and for coupling a second optical signal, which has a second wavelength which differs from the first wavelength, out of the fiber. The two signals travel in the transmission glass-fiber in opposite directions. The optical signals also travel in other, spatially separated glass fibers. The device includes an imaging device arranged between the transmission glass-fiber and the other glass fibers. In the pupil of the imaging device, a binary optical grating is disposed. Other glass fibers receive the second optical signals which have been diffracted into the diffractions orders of the grating.The grating is a phase grating and is arranged on an optical axis of the imaging device. It has a duty factor of at least substantially 1:1 as well as an optical path difference, H=(n-1)h, which is substantially(N-1)h=n.sub.1 .lambda..sub.I, where n.sub.1 =1, 2, 3, . . .and(N-1)h=(m.sub.1 +1/2).lambda..sub.k where m.sub.

Abstract: A device for spacially separating specific spectral regions, preferably of color components from a wideband spectrum which is actively and/or passively radiated by objects. The spectral regions, or color components, are derived from the diffraction orders of a diffraction grating (phase grating), which is disposed in the pupil of an imaging lens and whose groove profile consists of several steps, which produce path length differences which are integral multiples of a specific wavelength.

Abstract: The invention relates to a method of eliminating errors in images of patterns which consist of periodically arranged individual images by optical filtering, only certain selected diffraction orders of the regular pattern to be imaged in the form of a ring or parts of a ring being employed for further imaging.

Abstract: A method of image enhancement is described. A number of images of different unsharpness are separately filtered and subsequently combined. The various filters have complementary apertures.