New materials are expected to lead to ultra-fast full-optical communication technology, It’s 10 time

On August 10, 2015, researchers at Purdue University in the United States developed a new “plasma oxidation material” that promises to deliver ultra-fast full-light communication technology, at least 10 times faster than conventional technology. Optical communication uses laser pulses to transmit information along optical fibers for telephone service, Internet and cable TV. All optical technology, whether it is data flow or control signal, both light pulse, without any electrical signal to control the system. For data transmission, the amount of light that can be modulated is a necessary condition, says Nathaniel Kinsey, a doctoral student and lead author of the paper. “We can design a membrane to increase or decrease the reflected light, and use the increase or decrease of the light reflection to encode the data, and the change of reflection will result in the change of transmission.” The researchers demonstrated that the optical thin film materials made by aluminum doped zinc oxide (AZO) are modulated. In their use aluminum doped zinc oxide, zinc oxide was saturated with the optical properties of the aluminum atoms to change material, make it under a particular wavelength as a metal, while in other wavelengths as high resistance media.
AZO film’s refractive index is close to zero, which can control the light by using the electron cloud surface to control the light. The pulsed laser will change the refractive index of AZO, thus modulating the amount of reflected light. This material can work in near-infrared spectral range, which can be used in optical communication and is compatible with complementary metal oxide semiconductor (CMOS).
The researchers envision using this material to create an “all-optical plasma modulator,” or optical transistor. In electronics, the silicon – based transistor is responsible for switching power and amplifying signals. Optical transistors are used to perform similar tasks using light instead of electricity, which can speed up the system.
Using a pulse laser to illuminate the material, the electrons in the material move from one energy level to a higher level, leaving holes and eventually recombining with the holes. The speed of the transistor switch is limited by the time it takes to complete the cycle. In their AZO films, the cycle is about 350 femtoseconds, about 5,000 times faster than crystalline silicon. Converting this speed to the device is at least 10 times faster than the traditional silicon based electronics.