The research, published in the journal Nature Physics, was led by Dr. Akshay Naik and Professor Stefan Maier from the Cavendish Laboratory at the University of Cambridge. They used a technique called photothermal deflection spectroscopy to measure how light from a low-energy laser beam bent plastic.
When light hits an object, it can be reflected, absorbed, or transmitted. In the case of plastic, most of the light is transmitted, but a small amount is absorbed. This absorbed light causes the plastic to heat up, which in turn causes it to expand. The expansion of the plastic creates a gradient in the refractive index of the material, which bends the light.
The researchers found that the amount of bending depended on the wavelength of the light. Shorter wavelengths, such as blue light, bent the plastic more than longer wavelengths, such as red light. This is because shorter wavelengths have more energy than longer wavelengths, so they cause more heating of the plastic.
The researchers also found that the bending of the plastic could be controlled by the intensity of the light. At low intensities, the bending was small, but as the intensity increased, the bending became more pronounced.
This discovery has the potential to lead to new ways of manipulating light for applications such as optical communications and imaging. For example, it could be used to create optical switches that are controlled by light, or to develop new types of lenses that can focus light more precisely.
The researchers say that the next step is to investigate how this effect can be used to create practical devices. They also hope to explore the possibility of using other types of materials, such as metals or semiconductors, to achieve similar effects.
