{'fraction_non_alphanumeric': 0.014666666666666666, 'fraction_numerical': 0.0013333333333333333, 'mean_word_length': 5.530434782608696, '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}}
Diffractive optics in modern optical engineering

The influence of diffractive optics on modern optical engineering has been considerable. The paper discusses a wide variety of applications of diffractive surfaces in the infrared and visible wavebands. Successful developments in low mass and multi-waveband infrared optics are described and results presented from manufactured hardware. The use in the visible waveband for real-time 3-D imagery, high power magnification of full colour displays, and possible use in diffractive-only helmet displays are examined for their potential. The limitation in the use of conventional diffractive surfaces for wide spectral bandwidth applications is described along with a method for alleviating this problem.