Apparatus for and method of verifying etching of optical servo information on magnetic media

摘要

An apparatus and method for etching a point on the surface of a magnetic medium to reduce the reflectivity of the point and for verifying that proper etching occurred. A light source provides a collimated incident beam of light. The incident beam is focused to a point on the medium and a portion of the beam is reflected. The reflected beam is separated from the incident beam and the intensity of the reflected beam is measured. The measured intensity is compared to a threshold value and verification is indicated if the measured intensity exceeds the threshold value.