General

When laser radiation interact with photorefractive (PR) crystal, photoinduced light scattering (see fig. 1) appears as a process of self-amplification of seeding scattering being induced due to diffraction on noise phase holographic gratings.

 

Fig. 1 Photoinduced light scattering


In presence of several light beams inducing photorefractive processes in the crystal, cone-shaped types of PILS can be observed if appropriate phase synchronism conditions are realized. Such PILS types asfour wave cross scattering (fig. 2) and photoinduced dispersion (fig. 3) were first observed and investigated in our laboratory.

 

Fig. 2. Four wave cross scattering

 Fig. 3. Photoinduced dispersion

 

 Another interesting type of PILS first revealed by us can be induced when PR crystal is illuminated along its optical axis. This scattering called autowave light scattering appears in the form of periodically arising light cones (fig. 4).

 

Fig. 4. Autowave ring

 

Photoexcitation of PR crystal can lead to photoinduced repolarization with origin of needle-like microdomain array (fig. 5). The latter can be displayed by appearance of conic light scattering called photomicrodomain light scattering (fig. 6)

 

Fig. 5. Photoinduced microdomains

 Fig. 6. Photomicrodomain light scattering