| 摘要 |
PROBLEM TO BE SOLVED: To obtain a quick response optical modulating device for high-density recording of an optical pickup for recording and reproduction. SOLUTION: This device includes a light source (1), an optical modulator (4), and two lenses (2 and 3) between them, and the distance between those lenses (2 and 3) is shorter than the sum of their focal lengths. The device which is optimized under those conditions can adjust the size of a light spot in the center of the optical modulator (4) by shifting only the positions of the lenses without varying the overall length from the light source (1) to the optical modulator (4). Therefore, the response time in optical modulation for high-density recording is shortened according to desired specifications to enable optimization for obtaining high light efficiency. |
