Barium-strontium mobate crystals for optical information recording

Abstract

Cerium-ion-doped barium-strontium niobate crystals are considered as a medium for information holographic recording. A brief account is given of the technology of crystal growth and of their optical and electrophysical properties. The laws of photoconductivity drop are established and the products of phenomenological parameters &3t are determined. The photorefractive characteristics of the crystal are investigated; the dependences of efficient sensitivity and amplification coefficient on spatial frequency are established. A new effect of light anisotropic scattering by crystals is observed and its interpretation is given. Finally holographic characteristics of the crystal are presented. Cer-dotierte Barium-Strontiumniobatkristalle als Medien fur holographische Informationsaufzeichnung werden untersucht. E s wird uber die Technologie des Kristallwachstums sowie uber deren optischen und elektrophysikalischen Eigenschaften berichtet. Die GesetzmLBigkeit des Photoleitungsabfalls und die Produkte der phanomenologischen Parameter ,uPt werden bestimmt. Die Lichtbrechungscharakteristiken des Kristalls werden untersucht; dabei werden die Abhangigkeiten der wirksamen Empfindlichkeit und des Verstarkungskoeffizienten von der Ortsfrequenz bestimmt. Ein neuer Effekt der anisotropen Lichtstreuung durch Kristalle wird beobachtet und seine Erklarung gegeben. SchlieBlich werden die holographischen Charakteristiken des Kristalls mitgeteilt. l) Leninskii prospekt 53, 117924 Moscow, USSR.

Optimization of a Rewritable Narrowband Filter in a Sbn:75 Crystal

“…On the other hand, highly efficient phase holograms can be recorded in SBN crystals, both in the external DC field [20,21] and through the diffusion recording mechanism [22]. Undoped samples of SBN are transparent in the visible spectral region [23][24][25]. Furthermore, it allows multiple optical erasure of previously recorded holograms [26].…”

Effects of La Doping on Microstructure and Ferroelectric Properties of BLTN Lead-Free Ceramics

“…The large EO coefficients are obtained in traditional lead-based electro-optic ceramics PLZT and PLMNT [4]. But the light modulator made from these lead-based electro-optic ceramics are difficult to do a fast response because of their large capacity, which is related to the EO material high dielectric constants [5,6]. Recently, the barium lanthanum titanate niobate Ba 6-1.5x La x Ti 2 Nb 8 O 30 (BLTN) ceramics with tungsten bronze structure is reported as a promising candidate as lead-free electro-optical materials [6].…”

“…But the light modulator made from these lead-based electro-optic ceramics are difficult to do a fast response because of their large capacity, which is related to the EO material high dielectric constants [5,6]. Recently, the barium lanthanum titanate niobate Ba 6-1.5x La x Ti 2 Nb 8 O 30 (BLTN) ceramics with tungsten bronze structure is reported as a promising candidate as lead-free electro-optical materials [6]. Noticeably, the BLTN ceramics has a lower dielectric constant, it is about the 1/5 ~1/10 of that of the lead-based EO materials, which could reduce the optical device capacity and further promote its response speed [7].…”

Frequency dependent electro-optic property of SBN single crystal

“…Their room temperature linear electro-optic coefficients increase with increasing Sr concentration across the solid solution range as a result of decreasing phase transition temperature. Several attempts to measure the electro-optic coefficients for pure or doped SBN were reported since Lenzo's work [1][2][3][4][5][6] , but there has been limited agreement among reported results [3,7,8] . The inconsistencies, to a large extent, may be attributed to the poling conditions and measurement boundary conditions, in addition to the temperature dependence of the optical birefringence, space charges effects, and crystal quality, among others.…”