- Tmt India
Nonlinear optics, Optical devices using nonlinear systems, Image processing and wavefront sensing and correction using liquid crystal spatial light modulators
For the last four decades, holographic memories, all-optical switches, wavefront sensing & correction and image processing have been the great white whale of technological research in optics. Holographic memories, it is now believed, could conceivably store hundreds billions of bytes of data per cubic centimeter, transfer them at a rate of a billion or more bits per second and select a randomly chosen data element in 100 microseconds or less. The main advantages of holographic storage – high density and speed – come from three-dimensional recording and from the simultaneous readout of an entire page of data at one time. A rather unique feature of holographic data storage is associative retrieval i.e. imprinting a partial or search pattern on the object beam and illuminating the stored holograms reconstruct all of the reference beams that were used to store data. Holographic memories store each bit as an interference pattern throughout the entire volume of the medium. The basic aim and objective of this project is to develop optical devices such as switches, gates and particularly high density memories using photorefractive crystals and biological systems such as bacteriorhodopsin using linear and nonlinear optical techniques.
Biological systems such as bacteriorhodopsin are being increasingly explored for their use in all optical devices. Optical information processing devices use light as a carrier for information by exploiting its inherent parallel processing capability. Optical processing systems based on non-linear materials such as bR etc. exploit the real-time recording characteristics of these materials and the parallel processing characteristics of optics, for faster data processing. Most of the work in this area is concentrated on non-linear optical properties because of the importance of these properties to the design of optical memories, optical computing and optical communication systems.
Real-time Adaptive Optical system with liquid-crystal spatial light modulator is being developed. Multi-segmented ferroelectric liquid crystal spatial light modulator (LCSLM) is used as a high precision wavefront control device for use in astronomical applications.
This laboratory with clean-room environment has been established at CREST to carryout research in the above discussed fields. This facility has BeamLokTM 2085 argon-ion laser from Spectra Physics (USA) is a high power (15W) cw laser with Z-Lok and J-Lok options. Solid-state diode-pumped Nd:YVO4) cw laser MillenniaTM V from Spectra Physics is used for pumping titanium doped sapphire (Ti: Sapphire) from Spectra Physics, USA. Tunable laser action over a broad range at near infrared (750-950 nm) makes it an excellent substitute for the dye lasers. The facilities include vibration isolation tables, wavelength meter, diode lasers, multi channel power meter, electronic balance, interferometer, CCDs, spatial light modulator, high quality optics and optomechanics, precision actuators and state-of-art motion controllers, LabView etc.