| 摘要 |
PURPOSE:To check crosstalk without providing a non-recording area by splitting a reference light beam into plural beams whose required angles are different, selecting the beam by a light shutter and radiating it with object light so that hologram can be recorded. CONSTITUTION:The collimated beam of laser from a laser element 31 is splitted into two beams by a beam splitter 33, one of which passes a beam splitter 34, a beam expander 37, a space light modulator 38 and a collimator lens 39 to become the object light 47. The other splitted beam passes the light shutter 36 and the lens 39 to become a 1st reference light beam. Another beam splitted by the splitter 34 passes a shutter 44 to become a 2nd reference light beam 46 in the same way. As for these light beams 45 and 46, the angles made by the line of a center axis projected to a recording medium with the center axis of a track on the recording medium are different values. One of the beams is selected by a control circuit 49 and the shutters 36 and 37 and the hologram can be recorded by using the different reference light beams every adjacent tracks. As a result, the crosstalk between the tracks can be checked without providing the non-recording area. |
