Search results for "Organic photorefractive materials"
showing 4 items of 4 documents
Photorefractive and photochromic effects in Sn2P2S6 at various temperatures
2013
Abstract Photochromic effect in nominally pure and doped Sn 2 P 2 S 6 photorefractive crystals is investigated in the temperature range 120–310 K. This effect determines a mechanism of the amplitude hologram formation at low temperatures, and we show that a competition between the photorefractive (phase) and the amplitude gratings occurs at increasing temperature.
Supplementary optical phase transition in photorefractive coherent oscillator
2001
The semilinear photorefractive coherent oscillator with two counterpropagating pump waves may exhibit two optical phase transitions: one from a disordered state of wide-angle photorefractive scattering into a high-ordered state with the immobile photorefractive grating and the other one from the state with immobile grating into the state with two moving photorefractive gratings. We show, both experimentally and from calculations, that two these phase transitions are the second-order phase transitions.
Slowdown and speedup of light pulses using the self-compensating photorefractive response
2011
We study theoretically the effects of pulse slowdown and speedup in ferroelectric Sn2P2S6 possessing a self-compensating photorefractive response. It is shown that both these effects can be implemented in one sample for sufficiently large values of the coupling strength. In contrast to other types of the photorefractive response (local and nonlocal), the output pulses do not suffer from strong spatial amplification and broadening.
Highly transparent and birefringent chromophores for organic photorefractive materials
1999
Abstract A series of chromophores for application in organic photorefractive (PR) materials is investigated by electro-optical absorption measurements (EOAM). This experimental technique yields information on the transition dipole moment μ ag , the ground-state dipole moment μ g , and the change of the dipole moment upon optical excitation Δ μ within the intense charge transfer (CT) band of the dyes. It is shown that the results of the EOAM experiment allow us to estimate the PR figures-of-merits (FOMs) of the chromophores by either perturbational two-level equations or Kramers–Kronig transformation. In particular, chromophores based on the heterocyclic dihydropyran and dihydropyridine grou…