A quasi-collinear and partially degenerate four-wave mixing model is proposed to explain the optical phase-conjugation property of various types of stimulated backscattering. According to this model, after passing through a phase-disturbed medium or an aberration plate, the input pump beam can be resolved into two portions: a stronger undisturbed regular portion and a weaker phase-disturbed irr...

Photogalvanic effect sPGEd or anomalous photovoltaic effect is a transport phenomenon producing high electric fields s,100 kV/cmd in ferroelectrics. PGE plays an important role in holographic-grating recording and was recently demonstrated for optical actuation and as high-voltage power supply. In this paper we demonstrate PGE generating highvoltage electrical pulses in atmosphere to apply this...

For optical data storage applications, it is essential to determine the lowest intensity (also known as threshold intensity) below or at which no data page or grating can be recorded in the photosensitive material, as this in turn determines the data capacity of the material. Here, experiments were carried out to determine the threshold intensity below which the formation of a simple hologram--...

Several theoretical models have been proposed to predict the behavior of photopolymers as holographic recording materials. Basically these models have been applied to study thin layers (around 100 microm thick). The increasing importance of holographic memories recorded in photopolymers (thickness of > 500 microm) makes it necessary to extend the ideas proposed by these models to study thick ph...

This paper reports the experimental approaches to the fabrication of two-layer integrated phase masks and the fabrication of photonic crystal templates using the phase mask based on holographic lithography technique. The photonic crystal template is formed by exposing photoresist mixtures to five-beam interference patterns generated through the phase mask. The fabricated phase mask consists of ...

Double-resonant extremely asymmetrical scattering (DEAS) is a strongly resonant type of Bragg scattering in two joint or separated uniform gratings with different phases. It is characterised by a very strong increase of the scattered and incident wave amplitudes inside and between the gratings at a resonant phase shift between the gratings. DEAS is realised when the first diffracted order satis...

A polymer-based graded index (GRIN with n= 1.4-1.6) waveguide lens was demonstrated on a semi-insulating GaAs substrate. The transparent bandwidth of the polymer film (photolime gel) is from -280 to -2800 nm. Therefore, UV (ultraviolet), visible and near-IR (infrared) light can be employed as the signal carrier wavelength. In this letter, an off-axis chirped grating lens working at 632.8 nm wit...

Synthetic aperture is a well-known super-resolution technique which extends the resolution capabilities of an imaging system beyond the theoretical Rayleigh limit dictated by the system's actual aperture. Using this technique, several patterns acquired by an aperture-limited system, from various locations, are tiled together to one large pattern which could be captured only by a virtual system ...

Electric field-resolved transient grating measurements are used to distinguish the four-wave mixing signal emission from a resonant solute and a non-resonant solvent. The two components of the solution (i.e., solute and solvent) emit signal fields at different times with respect to the arrival of the probe pulse to the sample. This gives rise to a recurrence in the temporal profile of the total...

We demonstrate a single frequency, 1.55 m wavelength laser based on an asymmetric twin-waveguide structure using a single growth step and a simple fabrication process. The external Bragg grating is formed on the passive ridge waveguide, optically coupled to the twin-guide gain section using a low loss, tapered mode transformer. The grating is produced by near-field holographic printing using a ...