{'fraction_non_alphanumeric': 0.02276707530647986, 'fraction_numerical': 0.012259194395796848, 'mean_word_length': 4.953125, '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}}
Characterization of an 18-channel TIR modulator for printing applications

A multiple channel optical modulator provides a means of parallel information processing and enables fast laser printing. We have studied a multiple channel optical modulator utilizing total internal reflection (TIR) and the electro- optical properties of LiTaO3 crystals. We characterized the multichannel TIR modulator by illuminating it separately with a source of a single mode coherent radiation (a Ti:Sapphire laser), and with a source of multimode radiation (a laser diode). The best contrast ratio (on/off intensity ratio) is 100:1, and a contrast ratio of 20:1 is achieved at a driving voltage as low as 60 V. No significant cross-talk has been observed at a modulation frequency of 10 Hz. We found that the response of the modulator is very strongly influenced by the spatial coherence of the illumination source. We also found the presence of a photorefractive effect induced by the high power density of the impinging light beam. This photorefractive effect is not permanent, and can be recovered if the laser illumination is removed for a period of time.