SGER: The Opto-Mechanical Effect in Glass - A Novel Phenomenon

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9816402JainCurrently, the conversion of an optical signal into mechanical signal has required working with the combination of electro-optic and piezo-electric type cross effects. The necessary intervention of electronics has meant both a loss of signal quality and additional expense. Recently, researchers at the University of Cambridge in the UK reported an opto-mechanical effect (OME) in glassy 50% arsenic-50% selenium films, which transforms an optical signal directly into mechanical strain. It is an exciting discovery, which has opened a new area of materials research. It has instantly led to the conception of many novel applications such as optical disk drive heads, nano-actuators or switches, nano-transducers, sensors, super-sensitive spectrophotometers, etc. However, for OME's exploitation in devices there is an urgent need to establish its origin and various characteristics, and to determine how its magnitude may be enhanced. This project focuses on the understanding and development of the new phenomenon in collaboration with the group at Cambridge. The properties and structure of semiconducting glasses based on chalcogens (e.g. Se, sulfides or selenides of Ge, Sb or As, etc.) are known to be sensitive to the light. The photons may affect the volume, amorphization/ devitrification, mechanical (e.g., plasticity), rheological (e.g., viscosity), optical (e.g., darkening, birefringence, luminescence),electrical (e.g., conductivity, dielectric constant), or the chemical (e.g., etching, dissolution) properties of the glass. These photo-induced changes may be classified into three categories depending on their stability: (a) permanent changes which cannot be recovered without destroying the sample, (b)changes which can be reversed by heating the sample to the glass transition temperature, and (c)changes which can be reversed simply by removing the light source, or exposing the specimen to appropriate light subsequently. The OME is a class (c) vector phenomenon which exhibits analog relationship between optical input signal and mechanical output. The complete orientation relationship between the polarization direction and stresses resulting from OME will be measured, along with the temperature dependence and kinetics. The relationship between the wavelength of inducing light and the magnitude or kinetics of OME will be determined. The electronic structure will be characterized and the surface composition of the glass will be monitored using high-resolution x-ray photoelectron spectroscopy (together with Auger spectra, as needed). %%%The recent discovery of an opto-mechanical effect in chalcogenide glass films has opened up new opportunities in the area of advanced photonics by possibly enabling direct conversion from an optical signal to a mechanical signal. Currently, this transformation occurs by 2 intermediate steps, which require expensive electronics and result in a loss of signal. Professor Jain, an expert in glasses, will collaborate with the researchers who discovered the opto-mechanical effect to study the basic characteristics and limitations of the effect so that it can be utilized in new devices. This project is funded as Small Grant for Exploratory Research because it is preliminary work on a novel idea and because of its high-risk/high-payoff nature.***