{'fraction_non_alphanumeric': 0.022727272727272728, 'fraction_numerical': 0.01756198347107438, 'mean_word_length': 5.591836734693878, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Non-stoichiometric control of LiNbO3 and LiTaO3 in ferroelectric domain engineering for optical devices

Abstract Photorefractive damage, photoconductivity, and photogalvanic currents of stoichiometry controlled LiNbO3 and LiTaO3 have been investigated. A nearly stoichiometric LiNbO3 single crystal shows a lower photorefractive damage resistance than congruent LiNbO3, however, crystals doped with a small amount of MgO (> 0.78 mol.%) exhibit no measurable photorefractive damage at 532 nm up to intensities of 2 MW/cm2. In the case of LiTaO3, it turned out that nearly stoichiometric crystals exhibit considerably high damage resistivity even without MgO doping. Green-induced infrared absorption (GRIIRA) in the crystals was also investigated by a photothermal technique. The GRIIRA in nearly stoichiometric LiNbO3 is found to be remarkably decreased by a small amount of MgO. GRIIRA in nearly stoichiometric LiTaO3 was strongly suppressed even without MgO doping.