In this study, we have derived equations for the pyroelectric and photogalvanic contribution to the electrical charging of
the photosensitive ferroelectric crystal. Standard photorefractive equations are supplemented by the equation of state for
the polarization density following the Devonshire-Ginsburg-Landau (DGL) approach. The photogalvanic voltage and
current is considered for a wide intensity range, which includes the CW and the pulsed photo-excitation with high
intensities when the impurity is fully ionized and when the traditional linear-recombination approach is not valid.
The crystal electrostatic accelerators, based on charging of ferroelectric crystals by pyroelectric and photogalvanic
effects, are discussed in relation to the generation of the self-focused electron beam, X-rays, and neutrons.
Single-beam phase conjugation (self-phase conjugation, or SPC) was observed in the ferroelectric crystal
LiNbO<sub>3</sub>:Fe using CW HeNe laser (wavelength 632 nm power 10-36 mW). Effective "out/in" reflection
coefficient of phase conjugation (defined as the ratio the output phase-conjugated beam to the input laser
beam measured before optical elements) was about 30%. For some crystals efficient phase conjugation was
followed by the simultaneous generation of Fabry-Perot modes. Phase locking of two HeNe lasers and
imaging of the amplitude objects with the help of self-phase conjugation was demonstrated. Appearances of
additional beams (in transmission and reflection) have some analogy with the predicted behavior of the
We have observed generation of the electron beam by the pyroelectric crystal placed in the vacuum
chamber. Different pyroelctric materials, Fe-doped LiNbO<sub>3</sub> and L-alanine doped TGS crystals, were tested.
Crystals of L-alanine doped TGS (LATGS) were grown by evaporation of the solution with 10% initial
concentration of L-alanine under T=45°C (somewhat below phase transition temperature T<sub>C</sub> = 49.9°C). In
this case crystallization proceeds immediately in the polar phase
Heating/cooling cycles of the crystals in the vacuum (P~ 1-5 mTorr) produce uncompensated surface
charges and strong electric field (~ 100kV/cm) on the polar crystal faces. These fringing fields ionize
ambient gas and accelerate electrons to high energies (~100 KeV). For photosensitive LiNbO<sub>3</sub> crystal
electrical charging and generation of electrons may be done by laser illumination, via photogalvanic effect.
These generated electrons can be detected by the fluorescent ZnS screen or by the X-rays produced by
placing copper plate in the electron beam. Model that explains and figures that depict the self-focusing of
the electron beam is presented.
Dynamic reflection gratings, recorded by the single laser beam in ferroelectric crystals covered by nano-structured
golden film generate optical and electrical pulsations. Frequency and amplitude of pulsations depend on laser intensity,
the ambient pressure and temperature.
Model explaining pulsations are developed based on the photogalvanic and pyroelectric mechanisms of holographic
grating recording. Possible applications for the remote pressure and temperature sensing are discussed.
Golden nanostructured film increase significantly sensitivity of the crystal pulsations to laser intensity, temperature and
pressure. For a focused HeNe laser beam (intensity about 160mW/cm<sup>2</sup>) an interesting phenomenon (deserving special
considerations) of self-phase conjugation was observed.