| 摘要 |
The present invention relates to a scanning interference microscope. The scanning interference microscope according to the present invention comprises: a light source; a polarized beam splitter (PBS); an acousto-optic (AO) device; an AO driving unit for driving the AO device according to a modulated frequency (fRF) for dithering within a frequency variable range (?f) and on the basis of a center modulated frequency (fRF0); a photodetector for detecting an interference signal of a signal light and a reference light; an RF demodulator using a modulated frequency in order to demodulate and output the interference signal; a lock-in amp using a dithering frequency (fdithering) in order to demodulate and output a signal supplied from the RF demodulator; a function generator for generating a dithering signal having a preset amplitude (A) and the dithering frequency (fdithering) and supplying the generated dithering signal to the AO driving unit, and supplying the dithering frequency (fdithering) to the lock-in amp; and a controller using a signal outputted by the lock-in amp in order to detect information on a sample. The scanning interference microscope according to the present invention uses the AO device, which is capable of: varying the modulated frequency in order to obtain information on a local slope of the sample, in order to be able to accurately measure the surface of the sample; and measuring the amount of change in the overall slope of the sample caused by an external change (noise), so as to be capable of taking a more stable measurement. |
