Travel Grant: RUI: Engineering of Two-Photon Nonlinearities in Bulk and Artificially Structured Semiconductors

拟议的研究将调查两个光吸收和 各种半导体材料中的相关自折射， 具有掺杂剂和生长的体和薄膜结构 技术. PI将使用开发的技术和知识 根据NSF授予ECS 8310625研究新材料。 这个NSF 赞助的工作表明，双光子吸收系数在 未掺杂的块状半导体可以预测在50%以内， 只有几个材料参数。关于其影响的问题仍然存在 杂质和缺陷。目前的研究已经导致了 非掺杂晶体双光子吸收预测模型的建立 体半导体和光霍尔技术的发展， 研究非线性吸收和随后自散焦。 的 在半导体中设计非线性的可能性， 故意制造缺陷和添加杂质以及使用 包括窄带干涉滤光器的薄膜结构， 将研究多量子威尔斯。私家侦探会合作 北德克萨斯州立大学和赫瑞瓦特大学的研究人员 大学，并与材料供应商，如休斯研究 实验室，德州仪器，普渡大学和圣母大学 大学 本研究旨在应用实验技术， 在过去的NSF赞助下发展了理论理解， 进行非线性双光子吸收的广泛研究， 各种半导体材料中的相关自折射 和薄膜结构。 这些研究的结果应该 广泛应用于光学双稳、光学 限制和切换，以及激光对光学材料的损伤。 一些大学和工业合作者正在提供样品 for this research研究.

The proposed research will investigate two-photo absorption and the associated self-refraction in various semiconducting materials in bulk and thin film structures with differeing dopants and growth techniques. The PI's will use the techniques and knowledge developed under NSF grant ECS 8310625 to investigate new materials. This NSF sponsored work showed that the two-photon absorption coefficient in undoped bulk semiconductors could be predicted to within 50% knowing only a few material parameters. Questions still remain about the effects of impurities and defects. Current researach has resulted in the development of a predictive model for two-photon absorption in undoped bulk semiconductors and the development of the photo-Hall technique to investigate nonlinear absorption and subsequent self-defocusing. The possibilities of engineering the nonlinearities in semiconductors by intentionally producing defects and adding impurities as well as using thin-film architectures including narrow-band interference filters and multiple-quantum wells will be investigated. The PI's will collaborate with researchers at North Texas State University and Heriot-Watt University, and with materials suppliers such as Hughes Research Laboratories, Texas Instruments, Purdue University and Notre Dame University. This reserach intends to apply experimental techniques and theoretical understanding developed under past NSF sponsorship to perform an extensive study of nonlinear two-photon absorption and associated self-refraction in a wide variety of semiconducting materials and thin-film structures. The results of these studies should have broad applications to such fields as optical bistability, optical limiting and switching, and laser-induced damage to optical materials. Several university and industrial collaborators are supplying samples for this research.