{'fraction_non_alphanumeric': 0.0228310502283105, 'fraction_numerical': 0.0106544901065449, 'mean_word_length': 4.823008849557522, '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}}
Achieving Complete Bandgaps by Self-Similar Spherical Structure Using Low Refractive Index Materials

A three-dimensional complete bandgap (CBG) in the visible range is achieved by a self-similar spherical photonic crystal (PC) fabricated using the materials with low refractive index. A novel holographic technique is developed to fabricate such a structure. A CBG with a width of 120 nm is obtained experimentally. Even though the light not passing through the center of the sphere incidents on the PC with an incident angle of 49, a 30-nm-wide CBG can still be kept. Theoretical analysis is also given in which experimental results can be well explained.