Dmit Class Materials, Third-order Nonlinear Optical Properties And The Response Time Of Study

In the "Information Age", our social and economic life is relying increasing on the cost-effective exchange and use of information. Mass information transmission,high transmission speed, quick response, excellent anti-jamming ability, good Signal-to-Noise are the trends of information field, such as information transmission and data storage. The appearance of optical fiber communications greatly alleviate such problems as low transmission speed, poor Signal-to-Noise and easy disturbance which puzzle people. In modem optical fiber communication systems, there are many optical-electronic-optical converstion apparatus. But these electronical componets have some disadvantages such as stow switching speed, clock displacement and serious crosstalk, which have become the "bottleneck" of optical fiber communication system. Utilizing all optical switches is an effective method to solve the problem. All optical switches use the third-order optical nonlinearity of materials, whose work principle can be described as follows. One laser beam inducing the change of refractive index of materials, signal beam transmitted in mate rials will produce accessional phase change to realizing the "On" or "Off" ofoptical switches. All optical switches can break through the tramsmission speed limits of electro-optical, acousto-optical, thermo-optical and micro electromechanical switches. Such advantages spur people to devote all optical switch research. Third-order optical nonlinear materials have some other applications, such as making optical power limiters. Following the appearance of picosecond and femtosecond lasers, the beam's optical power density can reach several hundreds of GW/cm~2. Under such intensity, people's eyes are easy to be hurt and experimental detectors are easy to be damaged. Materials' two-photon absorption and anti-saturation absorption, etc. can all be used to facture optical power limiters. Optical power limiters having quick response, broad protecting bandwidth, low limiting threshold and high transmission can effectively protect eys, detectors and other devices to be not damaged by lasers. Materials' third-order optical nonlinearity can be used in Q-switched and passively mode-loked ultrashort laser technology. Femtosecond lasers' Kerr Lens Mode locking thechnique uses materials' optical...