| 摘要 |
Ferroelectric materials are disclosed as reversible holographic recording media (25) for use in two-photon recording systems. The ferroelectric materials disclosed herein provide long-lived electronic states intermediate the ferroelectric material's valence and conduction bands. These intermediate states have a sufficiently long life (on the order of 1 to 100 milliseconds) that low-power continuous wave ("cw") lasers (1) can be used to record interference patterns on them. Thus, two-photon holographic recording systems are also disclosed which do not require high-power, short pulse length, mode-locked or Q-switched lasers. Rather, the disclosed holographic recording systems employ visible and near IR cw lasers such as diode lasers. The disclosed two-photon holographic recording systems provide for absorption of a first photon which excites electrons of holographic recording media to an intermediate state. Thereafter, upon absorption of a second photon, the electrons are promoted to the media's conduction band where they are arranged according to the interference pattern provided by the recording system. |
