Spectral Hole Burning in Hyperquenched Glassy Films and Biomolecular Gels: Science and Applications

本研究的灵感主要来自于一种多功能热喷涂超猝灭装置的开发，该装置用于液体的可重复玻璃化，并通过非光化学孔燃烧和其他光谱成功地应用于超猝灭水玻璃膜（HGW）中的四磺酸酞菁（APT）。在给定温度下研究具有不同制备历史（沉积温度，退火程序）的薄膜的能力，为进一步详细研究玻璃不同状态之间的热力学连续性/动力学可达性，无序诱导和其他机制的光学减相，电子-声子耦合和非光化学空穴燃烧的机制方面开辟了道路。为此，将在乙醇和甲醇的超淬火薄膜中使用磺化的al -酞菁和再间酚，并在乙二醇玻璃中使用菁染料HITCI。这些数据将与理论相结合，以验证孔燃烧和光子回波技术的结合是理解液体光学相干损失的一种有前途的方法。提出了一种与压力相关（5mpa）孔烧相适应的新型超淬火装置。它将用于确定，例如，未退火和退火的HGW薄膜（APT作为发色团）的相对可压缩性（5k）。这一点很重要，因为在低温下负责脱相的本禀两能级系统（TLSint）的密度在未退火的薄膜中比退火薄膜高5倍。因此，这将有可能验证TLSint与玻璃的多余自由体积密切相关的假设。在当前NSF资助下完成的工作也表明，APT在低温和高温（- 77 K）下在HGW中的孔燃烧性能明显优于其他分子非晶体系。项目负责人拟研究高含水量蛋白凝胶(如：“Jello”)，其易于制备和高光学质量使其对时域光存储器/处理应用具有吸引力。目标是在77 K时实现600的频率存储密度，比缓冲HGW中的APT高4倍。研究人员提出了更多关于APT在HGW中的研究，目的是了解与低温和高温下异常高效的孔燃烧相关的氢键转换，并测试APT/HGW（氘化）光存储器对由于孔燃烧和光诱导的孔填充造成的破坏性读出的显着弹性的预测。最后，将对退火和未退火的HGW薄膜进行红外烧孔实验，以确定非均匀展宽和振动激子耦合对OH拉伸带底层结构的贡献。对这种结构的理解是一个长期感兴趣的迷人问题，其解决方案与液态水的结构和分子间力有关。无序及其对复杂固体（如玻璃、聚合物和蛋白质）的构型弛豫、能量和电荷输运、光谱跃迁动力学和其他性质的影响，是物理学、生物物理学和化学界非常感兴趣的课题。这是可以理解的，因为理解受结构紊乱强烈影响的物理和生物现象既重要又非常具有挑战性。此外，这种研究已经并将继续揭示新的物理和化学。该项目涉及分子玻璃的构型弛豫和动力学，以及一类新型高效、高温持续光谱孔燃烧材料的开发，用于光存储/处理和其他应用。这些项目和其他项目旨在深入了解液体和玻璃中的光学相干损失与高温下光学存储器的破坏性读出之间的关系。

Abstract 9630781 Small The proposed studies are inspired mainly by the development of a versatile thermospray based-hyperquenching apparatus for reproducible vitrification of liquids and its successful application, with nonphotochemical hole burning and other spectroscopies, to Al-phthalocyanine tetrasulphonate (APT) in hyperquenched glassy films of water (HGW). The ability to study films at a given temperature with different histories of preparation (deposition temperature, annealing procedure) opens the way for further detailed studies of thermodynamic continuity / kinetic accessibility between different states of a glass, disorder-induced and other mechanisms for optical dephasing, electron-phonon coupling and mechanistic aspects of nonphotochemical hole burning. To this end, sulphonated Al-phthalocyanines and resorufin in hyperquenched films of ethanol and methanol and the cyanine dye HITCI in ethylene glycol glasses will be used. The data will be used with theory to test the suggestion that the marriage of hole burning and photon echo techniques is a promising approach to understanding optical coherence loss in liquids. Construction of a novel hyperquenching apparatus compatible with pressure dependent ( 5 MPa) hole burning is proposed. It would be used to determine, for example, the relative compressibilities (5 K) of unannealed and annealed HGW films (APT as the chromophore). This is important because the density of intrinsic two level systems (TLSint), responsible for dephasing at low temperatures, is a factor of 5x higher in unannealed than in annealed films. Thus, it will be possible to test the hypothesis that TLSint are intimately associated with the excess free volume of glasses. Work completed under the current NSF grant has also shown that the hole burning properties of APT in HGW at low and high temperatures (- 77 K) are significantly superior to those of other molecular amorphous systems. The Principal Investigator proposes to study APT in high water content protein gels (e.g. "Jello") whose ease of preparation and high optical quality make them attractive for time domain optical memory/processing applications. The goal is to achieve a frequency storage density of 600 at 77 K, a factor of four higher than that for APT in buffered HGW. Additional studies of APT in HGW are proposed, the objectives being to understand the hydrogen-bond switching associated with the exceptionally efficient hole burning at both low and high temperatures and to test predictions of a notable resilience of APT/HGW (deuterated)'s optical memory against destructive readout due to hole burning and light-induced hole filling. Finally, infra-red hole burning experiments with annealed and unannealed HGW films will be performed in order to determine the contributions from inhomogeneous broadening and vibrational excitonic coupling to the underlying structure of the OH stretching band. The understanding of this structure is a fascinating problem of longstanding interest, one whose solution bears on the structure and intermolecular forces of liquid water. %%% Disorder and its effects on configurational relaxation, energy and charge transport, the dynamics of spectroscopic transitions and other properties in complex solids, such as glasses, polymers and proteins, are subjects of intense interest in the physics, biophysics and chemistry communities. This is understandable since to understand physical and biological phenomena which are strongly influenced by structural disorder is both important and very challenging. Furthermore, such research has and will continue to reveal new physics and chemistry. This project is concerned with configurational relaxation and dynamics in molecular glasses and the development of a new class of efficient, high temperature persistent spectral hole burning materials for optical memory/processing and other applications. These and other projects are designed to provide insights on the relationship between optical coherence loss in liquid and glasses, and destructive readout of optical memory at high temperature.