{'fraction_non_alphanumeric': 0.022222222222222223, 'fraction_numerical': 0.015277777777777777, 'mean_word_length': 5.675925925925926, '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}}
Enhancement of terahertz radiation from GaP emitters by subwavelength antireflective micropyramid structures.

Subwavelength antireflective micropyramid structures, designed by rigorous coupled-wave analysis and fabricated by precision micromachining, are used to enhance the terahertz (THz) radiation output of optical rectification in GaP crystal-based emitters. An average 16% increase in the THz radiation power emitted by a 3 mm GaP crystal is experimentally demonstrated using an antireflective micropyramid grating with a period of 60 μm and a base angle of 55.5°. Optimized pyramidal-frustum gratings are shown to operate as highly efficient antireflective structures within an ultrabroadband range of 0.5-5 THz.