| 摘要 |
<P>PROBLEM TO BE SOLVED: To reproduce a signal with a high S/N ratio as compared with a conventional one. <P>SOLUTION: Information is recorded in a recording medium 2 by irradiating a desired storage region 13 with a laser beam to transfer the state of the desired recording region 13 into a second state. The power Pw of the laser beam during recording generates intense two-photon absorption in the recording region 13 and is large to the extent that photochromism from a first state to the second state is generated. Information is reproduced from the recording medium 2 by irradiating the recording region 13 with a laser beam having a wavelength λ and detecting the transmission beam intensity by a light receiving part 6. When the laser beam is made incident in the recording region 13 in the first state, a weak transmission beam is detected by the two-photon absorption of the laser beam. When the laser beam is made incident in the recording region 13 in the second state, an intense transmission beam is detected since the laser beam is not two-photon absorbed. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
