Abstract: An optical space switch includes a polarization controller, a beam splitter, a first reflection block and a second reflection block. The polarization controller has a first mode and a second mode. The polarization controller maintains the polarization of input light in the first mode and changes it by 90.degree. in the second mode. The first reflection block includes a quarter wave plate and a light path changing element. The input light from the polarization beam splitter is reflected by the first reflection block. During this time, the input light passes through the quarter wave plate twice. Thus, the polarization of the input light is changed by 90.degree.. Further, the light path of the input light is shifted by a predetermined distance by the light path changing element. The second reflection block has a quarter wave plate and a mirror. The second reflection block receives the input light from the polarization beam splitter, and returns it thereto.

Abstract: A Pockels effect electric field sensor includes, as a sensitive element, a crystal with electro-optic properties traversed by a luminous beam with specific polarization and propagation directions. The crystal is cut into the shape of an ellipsoid (14) and has a crystallographic symmetry being either uniaxial 622, 422 or 42m or cubic 43m or 23, the three perpendicular axes of the ellipsoid being orientated along three trirectangular crystallographic axes with the highest symmetry of the crystal.

Abstract: The concept of using only a component of an applied electric field to control the electrooptic response in each element of a multi-crystal electrooptic modulator comprising a matched grouping of birefringent electrooptic elements is disclosed. The foregoing concept permits the orientation of the polarization eigenvectors of the grouped elements to compensate for the effects of the static birefringence of the material comprising the elements while retaining the use of parallel applied electric fields and eliminating the need for an interposed optical rotator or waveplate.

Abstract: An optical modulator having a slit arrangement and an associated zone exhibiting both an electrooptical effect and an intrinsic polarization direction, includes an electrode arrangement to which an information signal is applied during operation. The slit arrangement is a double slit arrangement while the electrode arrangement includes three electrodes between which the slits are disposed. At one slit, the electrical field of the signal is oriented in the same direction as the intrinsic polarization direction and, at the other slit, the electrical field of the signal is oriented in a direction opposite to the intrinsic polarization direction.

Abstract: A traveling wave optical modulator on X-cut lithium niobate is disclosed which has improved bandwidth capability along with a low switching voltage requirement and good impedance matching. In accordance with another aspect of the disclosed invention, the impedance of a traveling wave optical modulator may be increased to a desired input impedance without adversely affecting the drive voltage or velocity matching of the modulator. This is accomplished by reducing the width of the ground electrodes to not more than 3 times the width of the hot electrode.

Abstract: An optical switch for arbitrarily polarized light having low cross-talk is made in which an input beam is split into its TE (s wave) and TM (p wave) polarization components, the TM component is converted to TE by total internal reflection, the two beams are either reflected or transmitted by liquid crystal cells, one of the beams is then converted to TM polarization, again by total internal reflection, and the two beams are recombined and outputted from one of two ports.

Abstract: A method of and a device for driving a light shutter having an electrooptical effect to polarize an incident light by applying an electric field to the light shutter. When the light shutter is made activate, an excessive electric field in addition to a half-wave electric field which is a specific one to polarize an incident light at 90.degree. in the static characteristics of the light shutter is applied to the light shutter initially, and subsequently, the half-wave electric field only is applied to the light shutter. To discharge the electric charge accumulated in the light shutter, no voltage is applied to electrodes each of which is provided on the wall of the light shutter so as to oppose each other subsequent to the application of the electric field until the next application thereof.

Abstract: An optical deflection device for manipulating optical beams employs a set of layers having the configuration NUPUN . . . , where the N and P symbols refer to N-type and P-type dopants and the U symbol refers to an electrooptically active optical guide layer having an index of refraction sufficiently higher than that of the N- and P- layers that light is guided within it and a free electron concentration low enough that the guide layers are depleted, so that light is guided within the layers with low loss, while the N- and P- layers have an appropriate bias applied to establish a differential phase shift between layers to deflect emitted radiation along a desired angle.

Abstract: An efficiency polarization converter of few optical components for converting a randomly polarized light into a single beam of linearly polarized light, comprises a first optical device receiving the random light and projecting two linearly polarized lights one projected in a first direction, another to a second optical device which changes the polarization plane thereof, the polarization changes light being directed by a third optical device to the first direction, thereby the two linearly polarized light are combined and aligned to have a common polarization to become the single beam linearly polarized light projected in the first direction. Typical first optical device is a polarization beam splitter, a typical second optical device is a quarterwave plate with a mirror, a halfwave plate or a Fresnel rhomb with a mirror, or a photomodulation material interposed between biased electrodes with a mirror, a typical third optical device is a polarization beam splitter, a prism or a mirror.

Abstract: A sensor utilizing a single electro-optic crystal for simultaneously measuring an electric field in three directions. By providing three light beams aligned along specific crystallographic directions and having specific polarizations, the crystal can simultaneously sense the electric field in three orthogonal directions. The crystal preferably has cubic symmetry and belongs to one of the point groups 43m or 23, such as crystals of bismuth silicon oxide or bismuth germanium oxide.

Abstract: A pair of fiber optic cables (12, 14) are connected at one end to a single light emitting diode (10). The second ends of the cables (12, 14) are connected to a first end of a polarized polyvinylidene fluoride film member (16), in a symmetrical relationship on opposite sides of a longitudinal centerline. The second end of the film member (16) includes a triangular recess formed by intersecting 45.degree. edges (82, 84). A beam splitter (18) is positioned in the recess, with opposite end portions, one positioned to receive a beam of light from cable (12) and the other positioned to receive a beam of light from cable (14). The beam splitter redirects the two beams towards each other and towards a diagonal split (72) at the center of the beam splitter (18). A change in length of the film member (16) on one side of the longitudinal centerline will change the phase relationship of the two light beams where they meet at the split (72). A fiber optic cable (20 ) is connected to the beam splitter (118).

Abstract: A spatial light modulating element including an electrooptic and photoconductive single crystal plate, a light-transmitting insulating layer provided on at least one of opposite surfaces of the electrooptic and photoconductive single crystal plate, and a pair of electrodes provided for applying an electric field to the insulating layer and the single crystal plate. The insulating layer is formed from a uniaxial single oxide crystal which is crystallographically oriented such that the insulating layer exhibits neither birefringence, nor an electrooptic effect in a direction of the electric field. The insulating layer may be a LiNbO.sub.3, LiTaO.sub.3 or TiO.sub.2 (rutile) single crystal plate cut normal to the (001)-axis.

Abstract: An optical unit having an electrooptical element whose optical properties are changed as a function of a voltage applied thereto to modulate an incident light in response to the applied voltage. The optical unit includes a shielding member for electrically shielding at least a portion thereof which includes the electrooptical element from an external electric field. The shielding member protects the electrooptical element from an influence of an external electric field on an electrooptical effect of the electrooptical element. The shielding member may be an electrically conductive member, such as a metallic casing accommodating the electrooptical element, or an electrically conductive layer covering a housing accommodating the element.