A method for measuring very small optical losses

摘要

The invention relates to photometry, optical fibres and the measurement of very small optical losses in other fields of optics. One object of the invention is to improve the accuracy of measurements, which is achieved by modulating the probe or test optical radiation at a frequency f <IMAGE> 0.1 δFsδ-3/2, forming a measuring channel and an optical channel, converting the optical radiation into electrical signals, simultaneously and in synchronization detecting said signals at a mismatch instant <IMAGE> and integrating them over a specific period of time on the basis of the formula: <IMAGE> in which: δzi is the relative instability of the probe radiation energy; δ is the maximum relative error of measurement; and δF3 is the frequency band of the electrical signal <IMAGE>