Distance measuring method, optical comb distance meter, and optical three-dimensional shape measuring apparatus

摘要

Problem to be solved: to provide a distance measuring method capable of measuring a distance to a subject continuously and accurately over a wide measurement range beyond a limit of a half wavelength measurement range, a distance meter and an optical three-dimensional shape measuring apparatus.Solution: first optical com reference light and measurement light of a first wavelength band in which the center frequency is different from each other are emitted from a first light sourceThe second optical comb reference light and the measurement light in the second wavelength band are emitted from the second light sourceReference light S1 which combined first and second reference lightThe measurement light S2 which has combined the first and second measurement light is incident on the interferometer 13.The reference interference light S3 obtained by combining the reference light S1 and the measuring light S2 and the reference light S1 passing through the reference optical path 21 of the reference optical path length L1 and the measurement light S2 passing through the measuring optical path 51 are combined to generate the measuring interference light S4.The phase difference between the first and second reference and measurement interference light signals obtained by detecting the interference light S3 obtained by the interferometer 13 and the interference light S4 obtained by the interferometer 13 by the signal processing section 17The distance L2 to the object is calculated.Diagram