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Item Exploration of rare-earth ion transitions and host materials for spectral hole burning applications and quantum information science(Montana State University - Bozeman, College of Letters & Science, 2021) Marsh, Aaron Daniel; Chairperson, Graduate Committee: Rufus L. ConeDue to their capacity for generating and manipulating light, the rare-earths are a foundational part of many cutting-edge technologies, ranging from lighting to quantum communications. Optical applications based on rare-earth doped materials are restricted to their transition energies. There are large bands, including the telecom window, where available rare-earth transitions typically have poor properties at liquid helium temperatures. The limitations are determined by the fundamental interactions between rare-earth ions and their host materials; comprehension of the interactions can be leveraged to significantly improve the properties of rare-earth quantum states. Three unexplored rare-earth optical transitions are investigated in this thesis: the Tm 3+ 3 H6<-->3 F3 at ~690 nm, the Pr 3+ 3 H 4<-->3 F 3 at ~1584 nm, and the Tm 3+ 3 F4<-->3 H 4 at ~1451 nm. The first transition suppresses non-radiative relaxation through engineering of the host material phonon spectrum. The 3 F 3 lifetime is extended to ~100 microsecond in Tm 3+ :KPb 2Br 5. The material Tm 3+:LaF 3 is also prepared for high-contrast spectral filtering in ultrasound-optical medical imaging sensitive to blood oxygenation at ~690 nm. Narrow 380 kHz holes are burned; simulations of hole burning indicate that ~60 dB of filtering contrast at ~3MHz is possible. Likewise, non-radiative relaxation is suppressed on the Pr 3+ transition at ~1584 nm in the low-phonon energy host RbPb 2Br 5. Four sites are revealed, with ~2-5 GHz spectrally resolved inhomogeneous broadenings, ~0.5-1 ms T 1 lifetimes, pseudoquadrupole level storage, and ~750 ns coherence times. This material is discussed for use as an L-band quantum memory. The excited state transition of Tm 3+ at ~1451 nm is then explored for quantum memories. High-resolution spectroscopy finds ~1 GHz inhomogeneous broadenings, ~6 ms lifetimes, and laser-limited ~30 MHz holes are burned. Techniques for measuring the properties of excited state transitions are described. Throughout, experimental methods and applications demonstrate the close relationship between lanthanide research and devices. Rare-earth doped crystals are used as an all-optical, high-resolution sensor package for characterizing cryostats in situ, and spectral hole burning characterizes laser performance as a real-time, ~1 MHz resolution spectrum analyzer. The exploration of rare-earth transitions is found to enable new research and new applications, with many other transitions yet to be explored.Item Coherent laser studies of nonlinear and transient phenomena in Tb³� activated solids(Montana State University - Bozeman, College of Letters & Science, 1988) Liu, GuokuiItem Photon echo studies of rare-earth-activated materials for optical memory and signal processing devices(Montana State University - Bozeman, College of Letters & Science, 1995) Equall, Randy WayneItem Laser frequency stabilization to spectral hole burning frequency references in erbium-doped crystals : material and device optimization(Montana State University - Bozeman, College of Letters & Science, 2002) Bottger, ThomasItem Simultaneous two-photon absorption of tetrapyrrolic molecules : from femtosecond coherence experiments to photodynamic therapy(Montana State University - Bozeman, College of Letters & Science, 2003) Karotki, Aliaksandr; Chairperson, Graduate Committee: Aleksander Rebane; Rufus L. Cone (co-chair)Simultaneous two-photon absorption (TPA) in tetrapyrrolic molecules is studied and its applications to two-photon coherence gratings and singlet oxygen generation for photodynamic therapy are demonstrated in this thesis. First ever comprehensive study of TPA properties of tetrapyrrolic molecules is conducted in this work. Two-photon transitions in two key spectral regions, red to green and blue to near-UV (transition wavelengths) are investigated. Physical mechanisms leading to enhancement of TPA cross section in tetrapyrroles are elucidated. Porphyrin molecules with greatly enhanced two-photon cross sections are obtained. Spectral coherence interference gratings are created by means of two-photon excitation with pairs of phase-locked femtosecond pulses in tetrapyrrolic molecules. First, gratings are detected by means of persistent spectral hole burning, which constitutes the first ever demonstration of spectral hole burning by simultaneous absorption of two photons. Next, the gratings are detected in fluorescence spectrum, which we use to study zero-phonon lines and phonon sidebands in two-photon transitions. Application of tetrapyrrolic molecules to two-photon photosensitization of singlet molecular oxygen is investigated. First, TPA properties of some known one-photon photosensitizers are investigated. Then, a new class of TPA based photosensitizers with greatly enhanced two-photon cross sections is developed. The generation of singlet molecular oxygen upon two-photon excitation of the new photosensitizers demonstrated for the first time, which opens up new perspectives for two-photon photodynamic therapy