Marvin B. Klein

Bio: Marvin B. Klein is an academic researcher from HRL Laboratories. The author has contributed to research in topics: Photorefractive effect & Laser. The author has an hindex of 30, co-authored 122 publications receiving 2956 citations.

Optical limiting with C 60 in polymethyl methacrylate

Abstract: We demonstrate optical limiting for the C60 fullerene in polymethyl methacrylate (PMMA) as a solid polymer host. It is shown that the optical-limiting behavior is consistent with excited-state absorption (reverse saturable absorption) as a mechanism. We suggest that a higher threshold for optical limiting compared with that of C60 in toluene is due to nonlinear scattering for the liquid. The performance of C60 in PMMA is compared with that in chloroaluminum phthalocyanine, N-methylthioacridone, King’s complex, and ruthenium King’s complex in PMMA. Optical damage thresholds are reported.

Optimal Properties Of Photorefractive Materials For Optical Data Processing

Abstract: Optimal properties of photorefractive materials for optical data processingGeorge C. Valley and Marvin B. KleinHughes Research Laboratories, 3011 Malibu Canyon Road, Malibu, CA 90265AbstractThe charge transport model of photorefractivity is used to evaluate four figures of meritthat can be used to characterize the performance of photorefractive materials. The figuresof merit are the steady -state index change, the response time, the energy per area to writea grating with one percent diffraction efficiency, and the index change per absorbed energyper unit volume (photorefractive sensitivity). These indices are evaluated as a function ofgrating period and applied external electric field for Bi12SiO20, a fast material with arelatively small electro -optic coefficient and BaTiO3, a slower material with a much largerelectro -optic coefficient. Methods for optimizing the materials are discussed.IntroductionPhotorefractive materials such as lithium niobate (LiNbO3), potassium niobate (KNbO3),'barium titanate (BaTiO3), strontium barium niobate (SBN) and bismuth silicon oxide(Bi12SiO20) are attractive new candidates for real -time optical data processing, (ODP);

Beam coupling in undoped GaAs at 1.06 microm using the photorefractive effect.

Abstract: We have observed beam coupling and degenerate four-wave mixing in high-resistivity, undoped GaAs at 1.06 microm that is due to the photorefractive effect. The photorefractive species is thought to be the deep donor EL2. The measured values of two-wave gain are comparable with those measured in Bi(12)SiO(20). The response time is measured to be 20 microsec at an intensity of 4 W/cm(2). This exceptionally fast photorefractive response time (compared with that of oxide electro-optic materials) is due primarily to the large mobility of GaAs.

Depth-resolved holographic imaging through scattering media by photorefraction

Abstract: A depth-resolved near-infrared imaging system has been demonstrated for recording three-dimensional images of objects embedded in diffuse media. Time-gated holographic imaging employing rhodium-doped barium titanate as the recording medium is used to acquire whole depth-resolved two-dimensional images in 1 s. Millimeter depth resolution has been achieved with a transverse resolution of ~ 30 microm.

Photorefractivity at 1.5 μm in CdTe:V

Abstract: We have for the first time demonstrated two‐beam coupling energy transfer at a wavelength of 1.5 μm. Beam coupling gain coefficients of 0.6 cm−1 have been obtained in vanadium ‐doped CdTe with only 5 mW/cm2 incident intensity. These gain coefficients exceed typical gain coefficients in GaAs at 1.06 μm wavelength by 50%. In preliminary measurements using the moving grating technique, we have measured a gain coefficient of 2.4 cm−1. Through adjustment of the doping level, CdTe:V can be used as a sensitive photorefractive material through the 0.9–1.5 μm spectral range.

Organic Optoelectronic Materials: Mechanisms and Applications

Abstract: Organic (opto)electronic materials have received considerable attention due to their applications in thin-film-transistors, light-emitting diodes, solar cells, sensors, photorefractive devices, and many others. The technological promises include low cost of these materials and the possibility of their room-temperature deposition from solution on large-area and/or flexible substrates. The article reviews the current understanding of the physical mechanisms that determine the (opto)electronic properties of high-performance organic materials. The focus of the review is on photoinduced processes and on electronic properties important for optoelectronic applications relying on charge carrier photogeneration. Additionally, it highlights the capabilities of various experimental techniques for characterization of these materials, summarizes top-of-the-line device performance, and outlines recent trends in the further development of the field. The properties of materials based both on small molecules and on conjug...

Optical limiting performance of C60 and C70 solutions

Abstract: OPTICAL sensors used in connection with bright sources such as lasers and arc welders must commonly be protected from damaging light levels by the use of optical limiters1. One approach to optical limiting makes use of materials whose optical transmittance decreases at high light levels2–5. For most protective applications, the response must be rapid and the saturation threshold low; a lower threshold provides a greater safety margin. Studies of the optical properties of C60have shown that the absorption cross-section of the photoexcited triplet state is greater than that of the ground state6, suggesting that it may have a nonlinear optical response of the sort useful for optical limiting. Here we report measurements of the optical response of solutions of C60 and C70 in methylene chloride and toluene, using 8-ns pulses of 532-nm-wavelength laser light. We observed optical limiting behaviour in all cases, with saturation thresholds equal to or lower than those reported for other optical-limiting materials currently in use.

[60]Fullerene chemistry for materials science applications

Abstract: Since their first detection and bulk production, the fullerenes have gained a primary role on the scientific scene, reaching their climax when the 1996 Nobel Prize for Chemistry was awarded to Kroto, Curl and Smalley for their seminal discovery. The unique physical and chemical properties of these new forms of carbon led many scientists to predict several technological applications. This created a heavy disappointment when it was clear that fullerene-based materials would not soon be ready for the market. However, the fullerenes have so far delighted several dozens of researchers who found that C 60 and its relatives undergo a variety of chemical reactions. In most cases, the new derivatives retain the main properties of the original fullerene, and it is now not unlikely that some functionalized fullerenes may find useful applications in the field of materials science and technology. In this Article we summarize the basic principles of the organic chemistry of fullerenes, together with a description of the physicochemical properties that have made these carbon cages popular in materials science, and review the most recent achievements in the functionalization of fullerenes aimed at the production of new molecular materials.