| 摘要 |
<P>PROBLEM TO BE SOLVED: To increase light for an APC without reducing the quantity of the light used for recording and reproducing. <P>SOLUTION: A first diffraction hologram 13a for separating a central part 12a of elliptic exit light from a semiconductor laser 11 to zero order diffracted light 16 for recording and reproducing and first order diffracted light and a second diffraction hologram 13b for forming the first order diffracted light for the APC by diffracting a peripheral part 12b of the elliptic exit light with arbitrary diffraction efficiency are formed on a sheet of hologram glass 13. <P>COPYRIGHT: (C)2003,JPO |
