{'fraction_non_alphanumeric': 0.026515151515151516, 'fraction_numerical': 0.022727272727272728, 'mean_word_length': 5.147286821705427, '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}}
Normal-incidence intersubband hole absorption in In0.5Ga0.5As/Al0.45Ga0.55As quantum wells

Normal incidence absorption between valence band states is demonstrated in high indium content InGaAs/AlGaAs quantum wells (QWs) grown on GaAs. We report absorption at energies up to 300 meV (4.13 micrometers ) and integrated absorption fractions as high as 56 mAbs-meV per QW. The dependence of the absorption strength and peak energy on well width, barrier width, doping concentration, and doping profile is explored. It is found that a stronger absorption is obtained with the same sheet doping density for structures where the doping is in the barriers. We also discuss the differences observed between transverse magnetic and transverse electric incident polarizations in the absorption spectra.