Patent ID: 8976433
Filing Date: 2015-03-10
Classification: G01N,G02B,G03H

Abstract:
1. An apparatus comprising: a low-coherent light source for recording configured to emit an electromagnetic wave for recording; a mirror which is movable; a beam splitter configured to split the electromagnetic wave for recording into a reference beam heading for the mirror and an object beam heading for a medium; a detector configured to detect an interference pattern formed by the object beam coming from the medium and the reference beam reflected by the mirror; a light source for irradiation configured to emit an electromagnetic wave for irradiation; and a spatial light modulator configured to modulate a wavefront of the electromagnetic wave for irradiation by using information about the interference pattern detected by the detector, so as to irradiate the medium with an electromagnetic wave for irradiation having the modulated wavefront, wherein the mirror is configured to adjust an optical path length of the reference beam between the beam splitter and the detector, so as to set a specific depth inside the medium by matching the optical path length of the reference beam between the beam splitter and the detector with an optical path length of the object beam originated from the specific depth inside the medium between the beam splitter and the detector, wherein the spatial light modulator modulates the electromagnetic wave for irradiation into a phase conjugation wave of the object beam originated from the specific depth inside the medium by using the information, and wherein the phase conjugation wave travels back to the specific depth inside the medium set by the mirror.