Abstract: An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90.degree. angle of incidence.

Abstract: An optical shutter-camera includes a first optical unit, a deflecting unit, and a second optical unit. The first optical unit receives image rays from a subject and outputs first optical image rays to form a first optical image of the subject. The deflecting unit includes a deflection member and a pumping unit. The deflection member is a nonlinear optical material whose refractive index is varied by beam radiation. The pumping unit radiates a pumping beam having a variable intensity to a required region of the deflection member and varies the refractive index of the required region to variably deflect optical paths of the first optical image rays. The deflection unit is positioned so that a deflection center of the optical paths of the first optical image rays, formed when the variable intensity-pumping beam in incident on the deflection member, substantially agree with a position where the first optical image is formed.

Abstract: An optical deflection device for redirecting and/or focusing a high-power collimated beam of light, comprising an optically transparent gas-filled hollow sphere, and a plurality of gas-filled lenses positioned within the sphere. When photorefractive or optically non-linear gases are used within the sphere and lenses, a second beam of light made to travel along the path of the original beam, will result in a local change of refractive index of the gas, thereby altering the path of the original beam. In separate embodiments thereof, the lenses may be mechanically repositioned, the internal pressure of the sphere varied, or a combination of these and the foregoing accomplished.

Abstract: An optical device that is optically neutral to normal light but absorbs highly collimated light is formed as a mosaic of optical cells. Each cell has at least two refracting surfaces and a non linear material at a focus internal to those surfaces. In one form, the cell comprises two pairs of lenses with a layer of non-linear light absorbent material interposed between the lenses of each pair. The lens elements can be one-power telescopes. A first lens element focuses highly collimated light at its entrance aperture on the non-linear layer. The intensity of the focused light causes the non-linear layer to become opaque or reflective and thereby reduce, or substantially block, the transmission of highly collimated light. The second pair of lenses inverts the re-collimated light exiting the first lens pair.

Abstract: An image processing apparatus having a third-order nonlinear stimulated photon echo medium (1). The photon echo medium (1) can store large numbers of images in the form of a Fourier transformed pattern by spectral modulation. The spectral modulation is carried out by sending optical pulses in an optical pulse train having (or not having) image information to the medium (1) so that the population in the ground and excited states are modulated after the passage of the pulse trains and pulses. The Fourier transformed pattern is converted back to temporal modulation, consisting of a sequence of echo pulses that reproduce the original data pulse train. By using the apparatus, ultrafast operation such as convolution and correlation between a number of reference images and a test image can be achieved.

Abstract: A light-modulated photoconductor, exhibiting a variable permittivity, provides the basis for various instrumentation devices and methods. In one embodiment, the light-modulated photocondcutor is used as a dielectric between conductive plates to provide a light-modulated capacitor (photocapacitor). One of the conductive plates may be transparent to facilitate application of the modulating light to the photoconductor. The light-modulated capacitor may be used for numerous applications, such as instrumentation used to, e.g., measure the work function of surfaces during processing or as a non-contact voltmeter. In another embodiment, the light-modulated photoconductor is used as a mirror or lens wherein the index of refraction is optically modulated. Such light modulated lens or mirror assembly may be used as a beam steering device, e.g., a solid state infra-red (IR) beam steering device.

Abstract: A light activated switching device is disclosed in which the receipt of a light signal is used to switch a light beam between two output ports. The input light beam is reflected from an interface between two regions having different indices of refraction when the light signal is present. The reflected light beam then exits through the first output port. In the absence of the light signal, the two regions have the same index of refraction, and the light beam passes through both regions and exits through the second output port.

Abstract: An optically-controlled lens is used to stabilize a plano-plano optical resonator. The lens is made of a material whose shape, refractive index, or both can be changed by optically-induced localized heating. A control light source is provided to irradiate the lensing element and cause the required heating. In an optically-pumped laser, the pump light may function as the control light. For a longitudinally-pumped Nd:YAG laser, a suitable optically-controlled lens can be tailored out of GaAlAs to give the appropriate amount of optical absorption at the pump wavelength, while being transparent to the lasing wavelength.