We report on the operation of double phase-conjugate mirror (DPCM). Two inputs to opposite sides a photorefractive barium titanate crystal, which may carry different spatial images, are shown pump same four-wave mixing process mutually and self-refracted without any external or internal crystal surface. This results in reproduction two images simultaneously. device is analyzed theoretically, applications image processing, interferometry, rotation sensing discussed. also demonstrate ring...

Recent developments, both theoretical and experimental, involving the nonlinear interactions of light in photorefractive crystals are reviewed. When pumped by beams various configurations, certain crystals, such as barium titanate (BaTiO/sub 3/), respond with self-build up gratings crystal formation new beams. The emphasis here is on these devices, known oscillators, mutual light-crystal which govern their operation, all-optical applications based oscillators.< <ETX...

We discuss the use of photorefractive four-wave mixing for coupling and locking lasers. A demonstration double phase-conjugate mirror semilinear passive mirror, pumped simultaneously by different lasers, is described. Cleanup a distorted laser beam using another local configurations phase lasers are discussed.

A double-pass image transmission through a single multimode fiber is demonstrated, using passive phase conjugate mirror. An application to interferometry based on sensing by implementing the and mirror as one arm of Michelson interferometer. Due unique properties self-pumped conjugator, nonuniform distortions caused modal dispersion in other aberrations are cancelled out, while uniform changes detected.

A new optical rotation sensor is described. It a ring passive phase conjugator in which the may consist of multimode fiber. nonreciprocal shift ‘‘passive’’ like fiber activates grating movement and subsequent frequency detuning beams photorefractive four-wave mixer. This device has advantages natural reciprocal behavior conjugate (essential for sensing) several adjustable controlling parameters. reveals class interferometry changes ring’s phases, beam’s intensities losses, mixing crystal’s...

A new method for steering light beams with automatic (self-aligning) Bragg matching is presented. This device enables, in principle, a large beam deflection range which not limited by the condition. It based on double color pumped photorefractive oscillator. Two input of different colors induce and pump dynamic four-wave mixing process BaTiO3 crystal two other common grating are self-generated. Steering achieved wavelength tuning one beams. about 1.7°, an efficiency ranging from 50 to 90%,...

We present a new technique for radio frequency (RF) phase-shift amplification based on RF interferometry and demonstrate it in an optical system. A striking feature of this amplifier is that the input phase noise not amplified together with signal, so sensitivity improves higher amplification. also predict case correlated amplitude noise, affected by noise. With 600 MHz modulated light 100, we resolution 0.2 mrad, giving distance 8 μm. postulate nanometric can be achieved sub-gigahertz modulation.

By varying the absorption coefficient and width of an intralipid-India ink solution in a quasi-one-dimensional experiment, we investigate transition between ballistic diffusive regimes. The medium's attenuation changes abruptly two different values within single mean free path. This problem is analyzed both experimentally theoretically, it demonstrated that location depends on scattering as well measuring solid angle.

We present and demonstrate a set of dynamic optical interconnects which are based on the double phase conjugate mirror with photorefractive wave mixing. These devices bidirectional, self-adjusting, controllable in real time. Uses various interconnection modes given.

Can two laser beams of different colors interact with each other to initiate a photorefractive oscillation in slowly responding (∼1 sec) crystal? We report on the operation this new nondegenerate four-wave mixing device, which and gratings are efficiently self-generated. An application for image color conversion is demonstrated. In an experiment, we used pumps combinations lines argon-ion (514.5, 496.5, 488, 476.5, 457.9 nm) He–Ne (632.8 nm). The crystal was BaTiO3 time constant order 1 sec.

The operation of the double phase conjugate mirror (DPCM) is described. It can be regarded as a bidirectional spatial light modulator and controllable filter. Two independent image-bearing beams that may derived from different lasers exchange their information they are coupled into each other in photorefractive crystal. The,DPCM also shown to an optical thresholder filtering device, displaying edge enhancement. We propose use resonator with two facing DPCMs implement iterative image...

A study of photorefractive wave mixing with image bearing beams reveals unique capabilities in spatial modulation, filtering, and cleanup amplitude phase modulated beams. We explain the negligible crosstalk various oscillators.

We analyze the effects of additional terms in nonlinear Schrödinger equation for spatial solitons, directly derived from Maxwell's equations with Kerr nonlinearity, on shapes bright and dark solitons a fixed polarization. Combining analytical numerical methods, we find that always render broader. The most essential result is fundamental limitation width subwavelength soliton: ratio FWHM soliton to wavelength cannot be smaller than 1/2, same 1/4.

A theoretical and experimental study of noise in Brillouin two-beam coupling is presented, which includes both the nondepleted depleted pump regimes. The signal-to-noise ratio (SNR) shown to be proportional weak signal input power as well intensity regime. Pump depletion causes SNR gain degrade significantly, leading an optimum working point gBIpL ≃ 20. minimum detectable per mode noise, predicted measured approximately 5 μW at λ = 1.06 μm, dependent on frequency temperature, while peak also...

We report on an experimental study of the self-frequency detuning in wave mixing oscillators with photorefractive barium titanate crystal. show its dependence a dc electric field crystal, optical phases oscillator cavity, and light intensity This resolves many aspects previously observed unexplained effects similar indicates existence internal

Optoelectronic chromatic dispersion (OED) is a significant source of effective in photodiodes. We present an experimental and theoretical study OED PN-type Si photodiodes photovoltaic cells report on very large these devices. As measured with the modulation phase-shift technique at frequency 4 kHz for slow devices, spectral sensitivity commercial photodiode approx. 0.02 deg/nm 720-850 nm wavelength band increases to 0.25 λ = 1µm. For cell, 0.09 this region. These values translate into parameter 10

It is known that PN-type photodiodes possess high optoelectronic chromatic dispersion (OED). Here we present a theoretical and experimental study of OED in PIN-type photodiodes. Applying the modulation phase-shift technique, Ge PIN photodiode exhibits ∼0.5 deg/nm sensitivity at 10 MHz modulation, corresponding to 1.4 ×10

We report an experimental study of Brillouin two-beam coupling in CS2 at 1.06 μm the regime below pump's stimulated scattering (SBS) threshold. Angular discrimination between pump and signal beams is employed. No competitive self-SBS (phase conjugation) was observed despite operation near SBS Image intensification by a factor 300 demonstrated with this configuration.

We introduce a method of achieving cross-gain modulation and slow light using the Brillouin nonlinearity in an optical fiber. demonstrate approximatetely 10 m/s group velocity this technique with milliwatts power at room temperature.

Using mutually modulated cross-gain modulation, Stokes optical frequency changes are converted into modulation phase with high sensitivity. In the slow-light transition regime, we demonstrate kilohertz sensitivity to carrier frequency. The is inversely proportional of pump and beams.

Heatstroke, a form of hyperthermia, is life-threatening condition characterized by an elevated core body temperature that rises above 40°C (104°F) and central nervous system dysfunction results in delirium, convulsions, or coma. Without emergency treatment, the victim lapses into coma death soon follows. The study presented was conducted with diffuse reflectance spectroscopy (DRS) setup to assess effects brain occurred during heatstroke mice model (n=6 ). It hypothesized DRS can be utilized...

We experimentally investigate the behavior of Fano-like plasmonic resonance lineshape in a simple system comprising subwavelength hole or particle illuminated by tightly focused Gaussian beam. observe that for small lateral displacement scatterer, k-space distribution wave exhibits strong spin-dependent azimuthal variation. attribute this phenomenon to sensitive light-plasmon coupling conditions arising due specific phase matching requirements. This effect is qualitatively described...