{'fraction_non_alphanumeric': 0.01764705882352941, 'fraction_numerical': 0.0058823529411764705, 'mean_word_length': 5.468354430379747, '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}}
Phototransistors Using Point Contact Structures

We report on the photoresponse of point-contact structures under laser illumination conditions. The point contacts showed phototransistor action with high responsivity of more than 105 A/W and a high on-off rate, probably due to the efficient hole localization in the point contacts. We demonstrate an optical subtraction circuit using two point-contact phototransistors and an optical amplifier using a point contact phototransistor and a light-emitting diode.