| 摘要 |
Method and device for optical inspection of a sample using spectral interferometry, wherein a beam (2″) emitted by a radiation source (1) is directed onto the sample (5) and a reference beam (2′) is directed onto a reference sample (4), and the spectral interference of both beams after being reflected on the samples or after passing the samples is recorded by means of a spectrograph (6); the interferogram I(ω) thus obtained is numerically derived with respect to the angular frequency ω. For the function I′(ω) thus obtained the zeros ωi are calculated numerically as solutions to the equation I′(ω)=0 and the frequency-dependent group delay τ(ω) is then calculated from the zeros ωi according to the equation τ(ωn)=&pgr;/(ωi+1−ωi), wherein i=1, 2 . . . and ωn=(ωi+1+ωi)2. |
