Topical Meeting on Photorefractive Materials, Effects, and Devices II最新文献_第9页

Development of a Space Interferometer Using LiNbO3-Fe Crystal as Holographic Support 以LiNbO3-Fe晶体为全息支撑的空间干涉仪的研制

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.pd8

J. Marry, Y. Bernard, F. Lefaucheuh, J.P. Cadoret

引用次数: 0

Transient Photorefractive Effect in Graded Gap Superlattices 梯度隙超晶格中的瞬态光折变效应

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.f1

S. Ralph, F. Capasso, R. Malik

引用次数: 0

Photorefractive Crystal Fe:KNbO3 and High Efficiency Self-pumping Phase Conjugation Mirror 光折变晶体Fe:KNbO3和高效自抽运相位共轭镜

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.j8

D. Shen, D. Jiang, X. Tong

引用次数: 0

Seeded Stimulated Photorefractive Scattering 种子受激光折射散射

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.e2

R. A. Mullen, D. J. Vickers, D. Pepper

{"title":"Seeded Stimulated Photorefractive Scattering","authors":"R. A. Mullen, D. J. Vickers, D. Pepper","doi":"10.1364/pmed.1990.e2","DOIUrl":"https://doi.org/10.1364/pmed.1990.e2","url":null,"abstract":"Stable phase conjugate reflectivities as high as 60% have been achieved with back-seeded stimulated photorefractive scattering (SPS) in a BaTiO3 crystal having too small a gain-length product for unseeded SPS. The beam-bending and build-up dynamics of the process are demonstrated by the three top-view photographs of the crystal reproduced in Figure 1. In Figure la, there is no external seed and, in this case, no self-pumped phase conjugation; the beam refracts into an a-face of the crystal, fans sharply to an angle of about 20° with respect to the c-axis, then straightens out to exit a c-face of the crystal. In Figures 1b and 1c, the sequence of steps leading to SPS are shown in the presence of a backward seed. In Figure 1b, the fanned light exiting the crystal strikes a non-specular, diffusive-type surface, the scattering from which acts as a back-injected seed and dramatically lowers the gain-length product threshold condition for stimulated scattering. The phase-conjugate reflection in Figure 1b is in the process of building up; pump depletion is already evident in this photo. Figure 1c is a photo of the steady-state beam trajectory inside the crystal.","PeriodicalId":385625,"journal":{"name":"Topical Meeting on Photorefractive Materials, Effects, and Devices II","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125152291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Theoretical Impurity Levels of Ni and V Ions in BaTiO3 in Relation to Photorefractive Effects BaTiO3中Ni和V离子的理论杂质水平与光折变效应的关系

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.b1

P. Moretti, F. Michel-calendini

引用次数: 0

Noise-free Photorefractive Image Amplifiers 无噪声光折变图像放大器

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.j1

H. Rajbenbach, A. Delboulbé, J. Huignard

{"title":"Noise-free Photorefractive Image Amplifiers","authors":"H. Rajbenbach, A. Delboulbé, J. Huignard","doi":"10.1364/pmed.1990.j1","DOIUrl":"https://doi.org/10.1364/pmed.1990.j1","url":null,"abstract":"When a weak optical signal is injected in a photorefractive crystal illuminated with a strong pump beam, it experiences gain via a two-wave mixing process.(1) A problem common to these amplifiers is the presence of noise sources that corrupt the quality of the emerging amplified optical signal. We propose and experimentally demonstrate the first technique, to our knowledge, capable of very significantly reducing the optical noise while maintaining high gain coefficients. Consider two-wave mixing in a slowly rotating crystal. First, we estimate the influence of a crystal rotation (angular velocity Ω around the point O) on the noise intensity in the output plane (Fig. 1a). A noise source located around point A radiates a complex wavefront whose component along the direction of the injected signal is represented by a plane wave of intensity IN (A is a crystal imperfection or interface). It is essential to note that the noise sources are bounded to the crystal and will consequently move with it. This is the basis for the process of discrimination between the noise gratings and the injected signal grating. In the Ox coordinate bounded to the rotating crystal, the interference pattern responsible for the formation of a noise grating around the point A is given by: IN(x,t) = I0 [1 + mN cos KN(t)x], where KN(t) ~ 2π(θ + Ωt)/λ is the time-dependent grating wave vector (we have assumed that the angles inside the crystal are small), I0 is the total incident intensity (I0 ~ IP0), θ is the angle between the beams inside the crystal, λ = λ0/n is the optical wavelength in the crystal with refractive index n, and mN is the fringe modulation.","PeriodicalId":385625,"journal":{"name":"Topical Meeting on Photorefractive Materials, Effects, and Devices II","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125437357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nanosecond Selfdiffraction Electrogyration in the crystal of Bi12TiO20 (BTO) Bi12TiO20 (BTO)晶体的纳秒自衍射电旋

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.d3

M. Brodin, V. Volkov, N. Kukhtarev, A. V. Privalko

引用次数: 0

Parametric Intermode Scattering in LiNbO3 Planar Waveguides LiNbO3平面波导中的参量模间散射

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.e1

A. Novikov, S. Odoulov, S. Shandarov, V. Shandarov

引用次数: 1

Photorefractive effects in the organic crystal 2-cyclooctyIamino-5-nitropyridine (COANP) doped with 7,7,8,8-tetracyanochinodimethane (TCNQ) 7,7,8,8-四氰基亚二甲烷(TCNQ)掺杂有机晶体2-环亚氨基-5-硝基吡啶(COANP)的光折变效应

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.pd1

K. Sutter, J. Hulliger, P. Günter

引用次数: 0

Characterization of Band-Edge Photorefractive Effect in Compound Semiconductors 化合物半导体带边光折变效应的表征

Topical Meeting on Photorefractive Materials, Effects, and Devices II Pub Date : 1900-01-01 DOI: 10.1364/pmed.1990.c1

A. Partovi, A. Kost, E. Garmire, G. Valley, M. Klein

引用次数: 0