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Igor Litvin and Liesl Burger |
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In another achievement, the work of scientists at the CSIR National Laser Centre, Liesl Burger and Igor Litvin, as well as their supervisor Dr Andrew Forbes, has been showcased on the front cover of the South African Journal of Science's latest edition. The paper is titled Simulating atmospheric turbulence using a phase-only spatial light modulator.
The trio are thrilled about their achievement and Burger says, "Our work is unique in that other studies have concentrated on the impact of turbulence on a laser beam. We have simulated turbulence mathematically and used a spatial light modulator (SLM) to describe the turbulence. She explains, "It is often observed that light propagating through the atmosphere has a tendency to randomly wander and fluctuate in intensity. For example, the twinkling of the stars is precisely this randomness in direction and intensity." Turbulence refers to any change in air density, which could be caused by local variations of temperature and pressure.
Their paper outlines the basic steps required to simulate atmospheric turbulence in the laboratory using an SLM, which is an instrument that imposes a phase modulation on a beam of light. "We believe that this approach of using SLMs for the simulation of turbulence is versatile and cost-effective, and allows for useful laboratory-scale demonstrations," the scientists say in their paper.
Co-author Igor Litvin, a Russian national and PhD student registered at Stellenbosch University, is no novice either. The 28-year old has already published 15 papers, locally and internationally. He has been at the CSIR for the past three years. Litvin says, "While China has advanced in the study of turbulence, our work here is the first of its kind in South Africa".
According to Burger, for applications where light must travel through the atmosphere - for better 'vision' in astronomy and superior signal delivery in telecommunications, for example - active techniques exist to compensate for the effect of turbulence. She says, "The use of adaptive optics for atmospheric turbulence correction is fairly common these days in both astronomical and military applications and hence our work has particular relevance in these areas".
Enquiries: CSIR Communication
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