Technologies for measuring thickness of an optical disc

Abstract

The disclosure includes a system, device, apparatus and programmed medium of measuring thickness of an optical disc by using an interference effect of the optical disc layer. Such a system can include: a spectroscope to separate light, reflected from a surface of an optical disc, into constituent frequencies thereof; an optical intensity measuring unit to measure intensities of the constituent frequencies, respectively, as a first spectrum of data; and a processor to do at least the following, convert the first spectrum data into a second spectrum of values that exhibits variation as a function wavelength and refractive index, transform the second spectrum using a Fast Fourier Transform, and detect a thickness of one or more of the spacer layer and the cover layer, respectively, based upon the transformed spectrum. The disclosed technologies have advantages for high precisely measuring thickness of an optical disc.