{'fraction_non_alphanumeric': 0.01693480101608806, 'fraction_numerical': 0.000846740050804403, 'mean_word_length': 4.737864077669903, '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}}
New measures of the refractive index in liquids using speckle patterns

New results obtained with the method to measure the refractive index in liquids by using a speckle pattern are presented. When a laser beam impinges obliquely on a transparent rectangular cell, its direction of propagation undergoes a lateral shift when the cell is filled with a liquid. The shift depends only on the refractive index of the liquid, on the distance between the parallel walls of the cell and on the incident angle. Similarly, if the cell is illuminated by a speckle pattern, the latter suffers a displacement when the liquid is introduced. A CCD camera records the transmitted speckle pattern before and after filling of the cell with the liquid. The images are stored in a PC and processed with software to obtain the refractive index. The advantage in determining the displacement through the use of a speckle pattern is that a sub pixel processing can be made of the shifting caused by the liquid. The refractive indices of some liquids were performed, with errors under 1%: acetone, alcohol, water, xylene, butanol, dilution of butanol in xylene and a saturated solution of salt in water.