Apparatus and method for measuring characteristics of light

摘要

An optical phase characteristic measuring apparatus includes a harmonic generator (2) for generating a harmonic wave from a fundamental wave of output light from a light source (1); a beam splitter (3) for splitting a fundamental-wave component of the output light and a harmonic component; a sample (5) disposed in one of optical paths along which light beams from the beam splitter (3) propagate; a unit that is composed of a signal generator (6) and a mirror (7) and is adapted to modulate the length of one of the optical paths; an optical mixer (8) for mixing the light beams containing the fundamental-wave component and the harmonic component; an optical separator (9, 10) for separating light output from the optical mixer (8) into a fundamental-wave component and a harmonic component; a first optical detector (11, 12) for detecting a fundamental-wave component of an output from the optical separator (9, 10); a second optical detector (13, 14) for detecting a harmonic component of the output from the optical separator (9, 10); and a phase detector (17) for detecting the phase difference between AC signals output from the two optical detectors (11, 12 and 13, 14). An optical amplitude/phase characteristic measuring apparatus has a similar structure but includes two light sources (101, 102), a sum-frequency generator (104), and other related circuits.