Abstract: Laser systems and methods configured to reconstruct an image of an object from an input comprising: the objects scattered intensity distribution (SID) and the objects compact support; the system comprising: a first lens and a second lens, in a four-focal telescope configuration; a gain with a minor at one end, at first end of the telescope, configured to amplify and reflect a received beam; a reflective spatial light modulator, at second end of the telescope, configured to selectively reflect intensity distributions of a received beam, according to their spatial location, the selective reflection is configured to maintain the intensity distributions of the objects SID; a spatial intensity binary mask, located between the telescope's lenses, comprising an aperture in the form of the objects compact support; the mask is configured to transfer only beams passing through the aperture. The reconstructed objects image is provided at least at the mask's aperture.

Abstract: Measuring polarization profile along an input optical beam cross-section using an optical system includes a polarization beam splitting assembly for splitting the input beam into a predetermined number of beam components with a predetermined polarization relation between them, and including a polarization beam splitter in an optical path of the input beam splitting it into beam components having a polarization relationship and a birefringent element in an optical path of the beam components for splitting each of them into a pair of beams having ordinary and extraordinary polarizations, thereby producing the predetermined number of output beam components. The pixel matrix is located in substantially non-intersecting optical paths of the output beam components and generates a number of output data pieces indicative of intensity distribution within the output beam components and data contained therein being indicative of the polarization profile along the input beam cross-section.

Abstract: A system and method are presented for use in measuring polarization of an optical beam. The system is configured and operable for determining polarization profile along a cross section of the input optical beam, and comprises an optical system and a pixel matrix. The optical system comprises a polarization beam splitting assembly configured and operable for splitting said input optical beam into a predetermined number of beam components with a predetermined polarization relation between them, the polarization beam splitting assembly comprising a first polarization beam splitter in an optical path of the input optical beam splitting said input optical beam into a first plurality of beam components with a certain polarization relation between them and a birefringent element in an optical path of said first plurality of the beam components for splitting each of them into a pair of beams having ordinary and extraordinary polarizations, thereby producing said predetermined number of output beam components.

Abstract: A resonator cavity (10A) and method are provided. The resonator cavity (10A) includes at least one gain medium (16) and end reflectors (12, 14) which define together longitudinal modes of light in the cavity, and further includes an intra-cavity beam coupler assembly (20). The beam coupler assembly (20) is configured to split light impinging thereon into a predetermined number of spatially separated light channels, and to cause phase locking and at least partial coherent combining of the light channels, having common longitudinal and transverse modes, in a double pass through the beam coupler assembly (20). The resonator cavity (10A) is configured and operable to produce at least one output combined light channel of a predetermined intensity profile.

Abstract: A resonator cavity (10A) and method are provided. The resonator cavity (10A) includes at least one gain medium (16) and end reflectors (12, 14) which define together longitudinal modes of light in the cavity, and further includes an intra-cavity beam coupler assembly (20). The beam coupler assembly (20) is configured to split light impinging thereon into a predetermined number of spatially separated light channels, and to cause phase locking and at least partial coherent combining of the light channels, having common longitudinal and transverse modes, in a double pass through the beam coupler assembly (20). The resonator cavity (10A) is configured and operable to produce at least one output combined light channel of a predetermined intensity profile.

Abstract: A resonator cavity (10A) and method and presented. The resonator cavity (10A) comprises at least one gain medium (16) and end reflectors (12, 14) which define together longitudinal modes of light in the cavity, and further comprises an intra-cavity beam coupler assembly (20). The beam coupler assembly (20) is configured to split light impinging thereon into a predetermined number of spatially separated light channels, and to cause phase locking and at least partial coherent combining of the light channels, having common longitudinal and transverse modes, in a double pass through the beam coupler assembly (20). The resonator cavity (10A) is configured and operable to produce at least one output combined light channel of a predetermined intensity profile.

Abstract: A method and device are provided for automatically generating a key and a conjugate key to be used in an optical code division multiple access system. The method comprises applying a down conversion process to pump input light to thereby produce down converted broadband signal and idler fields that are complex conjugates of each other. The signal and idler fields thus serve as the key and its conjugate. Also provided according to the invention is a method for use in coding/decoding a signal in an optical code division multiple access system.

Abstract: A resonator cavity (10A) and method and presented. The resonator cavity (10A) comprises at least one gain medium (16) and end reflectors (12, 14) which define together longitudinal modes of light in the cavity, and further comprises an intra-cavity beam coupler assembly (20). The beam coupler assembly (20) is configured to split light impinging thereon into a predetermined number of spatially separated light channels, and to cause phase locking and at least partial coherent combining of the light channels, having common longitudinal and transverse modes, in a double pass through the beam coupler assembly (20). The resonator cavity (10A) is configured and operable to produce at least one output combined light channel of a predetermined intensity profile.

Abstract: An optical resonator supporting two sets of simultaneously co-existent oscillation modes (30 and 31), having polarizations orthogonal to each other. Mode control elements (28 and 29), such as apertures and phase elements, are introduced into the resonator to allow only preferred modes to exist. The placement and orientation of the sets are designed such that the high intensity zones of one set fall on the nodes or low intensity zones of the other set in an interlaced pattern. Thus, in a laser resonator, better utilization of the gain medium (24) is achieved and the beam quality and brightness over multimode lasing are improved. This configuration improves the performance of high Fresnel number resonators, in both pulsed and continuous lasers, for applications such as scribing, drilling, cutting, target designation and rangefinding. An application of the intra-cavity coherent summation of orthogonally polarized modes is described, whereby azimuthally or radially polarized beams may be obtained.

Abstract: A discontinuous phase element (86, 204) is disposed between the reflector (20, 23) elements of an optical resonator in order to suppress unwanted modes propagating within the cavity, and to preferentially allow the existence of preferred modes within the cavity. The discontinuous phase element (204) operates by producing sharp changes in the phase distribution of the undesirable modes, so that their propagation losses are sufficiently high prevent their build-up. This is achieved by introducing a discontinuous phase change to these modes at locations where they have high intensity. At the same time, the desired modes suffer 0 or 2&pgr; phase change, or have low intensity at the discontinuity, and so are unaffected by the discontinuous phase element. Such elements can be used in a single element or a double element configuration, and can be used in passive cavities or active cavities, such as lasers.

Abstract: The invention provides a holographic optical device, including a light-transmissive substrate; a first holographic optical element carried by the substrate; at least one second holographic optical element carried by the substrate laterally of the first holographic optical element, and at least one third holographic optical element carried by the substrate laterally displaced from the first and second holographic optical elements; wherein the center of at least one of the first, second or third holographic optical elements is located outside a single, straight line.

Abstract: An electronic utility device is provided. The device includes a user input interface and a user output interface, the user output interface including a compact virtual display for providing visual information to the user, the compact virtual display including (a) a light-transmissive substrate; (b) an input diffractive optical element integrally formed with the light-transmissive substrate; (c) an output diffractive optical element integrally formed with the light-transmissive substrate laterally of the input diffractive optical element; and (d) an image source for producing a real image, the image source optically communicating with the input diffractive optical element so as to collimate the real image into plane waves transmittable along an optical path through the light-transmissive substrate, such that when the plane waves impinges on the output diffractive optical element the plane waves are focused to form a virtual image which correspond to the real image and which is viewable by the user.

Abstract: An optical resonator supporting two sets of simultaneously co-existent oscillation modes (30 and 31), having polarizations orthogonal to each other. Mode control elements (28 and 29), such as apertures and phase elements, are introduced into the resonator to allow only preferred modes to exist. The placement and orientation of the sets are designed such that the high intensity zones of one set fall on the nodes or low intensity zones of the other set in an interlaced pattern. Thus, in a laser resonator, better utilization of the gain medium (24) is achieved and the beam quality and brightness over multimode lasing are improved. This configuration improves the performance of high Fresnel number resonators, in both pulsed and continuous lasers, for applications such as scribing, drilling, cutting, target designation and rangefinding. An application of the intra-cavity coherent summation of orthogonally polarized modes is described, whereby azimuthally or radially polarized beams may be obtained.

Abstract: A multilevel diffractive optical element comprising a base and a plurality of phase zones having phase levels of a substantially identical height h, each phase zone being defined by a local modulation depth d and a local number of phase levels &xgr;=d/h, the local number of phase levels &xgr; per phase zone being a real number, an integer of which defines the number of complete levels in the phase zone, which complete levels have identical widths, and a fraction of which, in at least one phase zone, defines an incomplete level which is narrower than the complete levels, said local number of phase levels &xgr;=&xgr;(x, y) varying among different phase zones so as to provide corresponding variation of said local modulation depth d=d(x, y) whereby local diffraction efficiencies and consequently an overall diffraction efficiency of the optical element is arbitrarily controlled.

Abstract: A multilevel diffractive optical element comprising a base and a plurality of phase zones having phase levels of a substantially identical height h, each phase zone being defined by a local modulation depth d and a local number of phase levels &xgr;=d/h, the local number of phase levels &xgr; per phase zone being a real number, an integer of which defines the number of complete levels in the phase zone, which complete levels have identical widths, and a fraction of which, in at least one phase zone, defines an incomplete level which is narrower than the complete levels, said local number of phase levels &xgr;=&xgr;(x, y) varying among different phase zones so as to provide corresponding variation of said local modulation depth d=d(x, y) whereby local diffraction efficiencies and consequently an overall diffraction efficiency of the optical element is arbitrarily controlled.

Abstract: A multilevel diffractive optical element comprising a base and a plurality of phase zones having phase levels of a substantially identical height h, each phase zone being defined by a local modulation depth d and a local number of phase levels &xgr;=d/h, the local number of phase levels &xgr; per phase zone being a real number, an integer of which defines the number of complete levels in the phase zone, which complete levels have identical widths, and a fraction of which, in at least one phase zone, defines an incomplete level which is narrower than the complete levels, said local number of phase levels &xgr;=&xgr;(x, y) varying among different phase zones so as to provide corresponding variation of said local modulation depth d=d(x, y) whereby local diffraction efficiencies and consequently an overall diffraction efficiency of the optical element is arbitrarily controlled.

Abstract: This invention discloses an electro-optically controlled optical element including a diffraction grating, and a planar waveguide associated with the diffraction grating, the diffraction grating and planar waveguide being configured to undergo resonance of at least one of transmitted or reflected light at a wavelength which is selectable by means of an electrical input.

Abstract: A planar optical correlator including at least first and second optical substrates (30, 32), through which light propagates by means of total internal reflection, at least first and second holographic lenses (20, 22) on the first optical substrate and optical third and fourth holographic lenses (24, 26) on the second optical substrate, each of the first and second and third and fourth holographic lenses performing a Fourier transformation on the input light to their respective optical substrates, the substrates positioned such that the second and third holographic lenses at least partially face each other. A filter (36) is positioned between the second and third holographic lenses.

Abstract: A planar optical crossbar switch comprising two thin planar substrates, on each of which are recorded or attached two holographic lenses between which light propagates by means of total internal reflection. The first lens is a negative cylindrical lens, used to input the incident light signal to the substrate, and the second lens is a positive cylindrical lens. The two substrates are disposed at right angles to each other in such a way that the positive lenses are positioned one on top of the other with a spatial light modulator sandwiched between them or beneath them. A linear array of detectors collects the output signal from the negative lens on the second substrate.

Abstract: A triangulation optical system and method for determining at least one coordinate of a surface of an object, along at least one coordinate axis which is substantially transverse to the surface. The method includes the steps of providing incident light of a substantially wide wavelength bandwidth propagating along the axis. Passing the light through an axially dispersing optics so that the light of different wavelengths is focussed at different locations relative to the axis. The different locations defining a multi-colored measuring area and a distance between extreme locations along the axis defining a depth of measuring range. Further, off-axis imaging of the measuring area, detecting intensity of the image and determining the coordinate of the intersection of the surface with the measuring area.