Abstract: An amplifier arrangement for increasing power and energy includes a multipass cell and at least one gain medium, wherein the multipass cell has concavely curved mirrors and the gain medium is arranged within the multipass cell in such a way that the pump radiation passes through the gain medium multiple times and is absorbed by the gain medium and wherein a laser beam to be amplified passes through the gain medium, characterized in that the mirrors are designed and arranged such that a White multipass cell is formed and the pump radiation and the laser beam to be amplified have large cross-sections at the positions at which mirrors, gain media and other optical components are arranged.

Abstract: An optical arrangement for enlarging spectral bandwidths by nonlinear self-phase modulation for shortening ultrashort pulses using a multipass cell and a nonlinear medium. The nonlinear medium is arranged within the multipass cell, and a laser beam having ultrashort pulses passes through the nonlinear medium multiple times. The laser beam is coupled into the multipass cell by way of a shaping optical unit. The laser beam is shaped into an astigmatic beam and coupled into the multipass cell by way of the shaping optical unit.

Abstract: An ultra-weak light multispectral imaging method and an ultra-weak light multispectral imaging system, which can realize multispectral two-dimensional imaging of an ultra-weak light object by constituting a linear array from single-photon detectors of all response wavelengths and combining it with light-splitting technology. The ultra-weak light multispectral two-dimensional imaging system realizes high-resolution optical modulation by adopting the compressive sensing (CS) theory and the digital light processing (DLP) technology and using a linear array single-photon detector as a detection element; the ultra-weak light multispectral two-dimensional imaging system comprises a light filter, a first lens (1), a DMD control system, a second lens, a spectrophotometer, a linear array single-photon detector consisting of a plurality of single-photon detectors with different response wavelengths, and a central processing unit; and the sensitivity of the system can reach the single-photon level.

Abstract: A single-photon counting imaging system and method includes an optical filter, first and second lenses, a digital micro-mirror device (DMD) control system, a single-photon counter and a data processing unit. The DMD and first and second lenses convert two-dimensional image data into a one-dimensional sequence. The ultra-weak light is filtered by the optical filter, after which the ultra-weak light image onto the DMD through the first lens. The DMD controls the probability of the photons reflected to the second lens and the second lens controls focusing of the photons. The data processing unit and single-photon counter complete sparse reconstruction. The data processing unit converts the number of photons counted by the single-photon counter within a certain period of time into the probability of detected photon counts. A photon density image is reconstructed by adopting an optimization algorithm based on the measurement matrix on the DMD and the measured value.

Abstract: An ultra-weak light multispectral imaging method and an ultra-weak light multispectral imaging system, which can realize multispectral two-dimensional imaging of an ultra-weak light object by constituting a linear array from single-photon detectors of all response wavelengths and combining it with light-splitting technology. The ultra-weak light multispectral two-dimensional imaging system realizes high-resolution optical modulation by adopting the compressive sensing (CS) theory and the digital light processing (DLP) technology and using a linear array single-photon detector as a detection element; the ultra-weak light multispectral two-dimensional imaging system comprises a light filter, a first lens (1), a DMD control system, a second lens, a spectrophotometer, a linear array single-photon detector consisting of a plurality of single-photon detectors with different response wavelengths, and a central processing unit; and the sensitivity of the system can reach the single-photon level.

Abstract: The invention relates to a single-photon counting imaging system and a single-photon counting imaging method.

Abstract: The invention relates to a resonator system with at least two folding elements for folding the beam path. Said folding elements serve to restrict the divergence angle of the radiation. The inventive resonator system is further characterized in that the respective folding is caused by reflection on a reflecting surface of the respective folding element. The beam axis of the radiation and the surface normal of the respective reflecting area are positioned at an angle relative to each other that is greater than the critical angle for the total reflection but smaller than the sum of the critical angle for the total reflection plus the divergence angle of the radiation.

Abstract: An optical amplifier arrangement, including an amplifying medium, which exhibits an approximately rectangular cross section with a long edge and a short edge, as well as at least two highly reflecting mirrors, between which the amplifying medium is disposed, whereby the long or the short edge of the cross section is along the X axis or the Y axis; the Z axis is the optical axis; and the X, Y and Z axis form a rectangular coordinate system. The mirrors are designed and arranged in such a manner that one beam, which is to be amplified and beamed in by an oscillator, passes repeatedly through the amplifying medium in the XZ plane and is amplified; and the size of the beam to be amplified in the X direction becomes larger after each passage.

Abstract: In apparatus for multiplexing and/or demultiplexing at least two electromagnetic waves of different wavelengths &lgr;1, &lgr;2, the improvement comprising at least one polarizing element wherein, the waves enter into said element in a linearly polarized manner.

Abstract: Optically pumped amplifiers, in particular solid-state amplifiers, comprise an amplification medium (1) and an optical pumping arrangement (5) via which the pumping radiation is coupled to the amplification medium (1), the pumping radiation being formed before coupling. The volume of the amplification medium is only partially pumped; the pumped volume of the amplification medium is approximately rectangular in cross-section and approximately perpendicular to the optical axis; and the ratio of the width to height of the rectangular cross-section is greater than 1:8.

Abstract: An arrangement is disclosed for geometrically shaping a radiation field, in particular the radiation field of a diode laser array which propagates in the z direction and has a radiation cross section which is larger, in a direction defined as the y direction, which is perpendicular to the first, and has a lower radiation quality in said direction. X, y and z form a Cartesian coordinate system. The radiation is grouped into radiation fractions in the x direction and the radiation fractions are reoriented as regards their radiation cross sections. The arrangement has at least two reflective elements (6) and is characterized in that each reflective element has a pair of reflection surfaces (7,8) at approximately or exactly 90° to each other. This opening angle (9) is oriented against the direction of propagation. The line (10) at which the reflection surfaces intersect is oriented at approximately below 45° to the x direction.

Abstract: A process and device for forming and guiding the radiation field or one or several solid and/or semiconductor lasers, in particular the radiation field of an array or field arrangement of one or several solid and/or semiconductor lasers, comprise radiation transformation optics with refractive elements that generate a defined radiation field. The device is characterized in that the radiation field (4) is subdivided into at least two radiation fractions according to predetermined data. Each radiation fraction enters an associated refractive element (6, 15, 19, 21, 23, 24) with predetermined co-ordinates. Each refractive element (6, 15, 19, 21, 23, 24) refracts the corresponding radiation fraction on at least one of its surfaces (7) so that the radiation fractions leave the refractive elements (6, 15, 19, 21, 23, 24) with output co-ordinates and/or propagation directions modified in relation to each other.

Abstract: The invention concerns an arrangement for shaping the geometrical cross-sion of a radiation field of a plurality of solid and/or semiconductor laser, in particular a plurality of diode laser arrays or field arrangements whose beam-outlet openings extend in a direction lying in the x-y plane and whose ray beam is radiated in the z direction, the x, y and z directions establishing a rectangular co-ordinate system, with an optical structure for generating a defined cross-section for a radiation field. The optical structure comprises reflective elements onto which the radiation of the respective lasers or laser field arrangements is guided and at which the radiation is reflected.

Abstract: The present invention relates to a process and device for forming and guig the radiation field of one or several solid and/or semiconductor lasers.

Abstract: An arrangement in which a reflection lens system shapes and guides beams from a rectilinear laser diode array with beam outlet surfaces lying in a common plane is disclosed In order to map the beams from the individual laser diodes to form a substantially uniform radiation field or pattern using such an arrangement, at least one first reflection component having a reflection surface is associated with each beam in order to bring together the individual outlet beams. The reflection surfaces are disposed in mutually offset planes, the offset corresponding sequentially to the sequence of the laser diodes in the array.

Abstract: A laser resonant cavity for utilizing media, having an annular cross sect as well as two end mirrors. The end mirrors exhibit a toroidal surface, and at least one end mirror has at least one aperture through which the laser beam can be coupled out.

Abstract: Laser resonator, particularly for carbon dioxide lasers, with two resonator nd mirrors having active material between two fully reflecting end mirror faces, which form an unstable resonator cavity, and with at least one third, completely reflecting mirror face reflecting the laser radiation prior to its coupling out through a coupling-out opening of the resonator. So that the laser only requires a reduced degree of coupling out and/or has an improved beam quality, it is constructed in such a way that, in addition to the unstable resonator cavity, between the two end mirrors is provided at least one stable resonator cavity and that the stable resonator cavity is made from the same active material of the third mirror face as the face of one of the two end mirrors with the face of the other end mirror.

Abstract: Aerodynamic window for a gas laser, whose active chamber emits a focussed ser beam and is flow connected by means of a beam passage opening with a window chamber connected to a vacuum pump and which has a beam exit opening in an outer area which is preferably under atmospheric pressure. In order to reduce the pumping power necessary for the aerodynamic window and improve the laser beam quality, the window is so constructed that the laser beam emitted by the active chamber has a first focus in the vicinity of the beam passage opening and is deflected onto a focussing mirror arranged in the window chamber and which gives the laser beam leaving the latter a second focus located in the vicinity of the beam exit opening.

Abstract: An aerodynamic window for gas lasers, has an active chamber with a beam penetration opening free of solids. An end of a beam duct is connected to the beam penetration opening and is transversely penetrated by a nozzle duct of a gas flow window through which compressed gas can flow. A beam outlet opening delivers a laser beam to an exterior space which is preferably at atmospheric pressure. A suction chamber of a differential pump is provided between the other end of the beam duct and the beam outlet opening, and the working pressure of the differential pump is approximately equal to the pressure in the other end of the beam duct on the suction chamber side.

Abstract: A laser has a beam path multiply folded by two resonator end mirrors and at east one reflector retroreflectively folding the laser beam. The laser axis is parallel displaced to the axis of a further reflector. In order to improve the laser beam quality while retaining its comparatively low adjustment sensitivity, the beam path is folded at least twice with the retroreflective reflector.