{'fraction_non_alphanumeric': 0.030474040632054177, 'fraction_numerical': 0.03160270880361174, 'mean_word_length': 4.0685714285714285, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, '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}}
Growth And Optical Properties Of Single-Crystal Sapphire Fibers

Sapphire single-crystal fibers are very promising for applications in high power laser delivery systems operating in the mid-infrared, e.g. the Er:YAG line at 2.9 μm. The fibers are nontoxic and chemically resistant. Also, they are mechanically strong and can be bent to a radius of less than 10 mm without breaking. Fibers with diameters of 110 μm and lengths of up to 1 m were grown by the laser-heated pedestal growth method. The minimum loss of 0.5 dB/m was measured in the near infrared at 1064 nm. An absorption band centered at 400 nm resulted in losses of up to 20 dB/m. Absorption loss at the Er:YAG line is 0.88 dB/m for a fiber grown in an atmosphere of pure oxygen. A damage threshold higher than 1.2 kJ/cm2 was measured for 110 μs long pulses, making tissue ablation feasible with fibers several meters long.