It seems impossible to achieve light emission through opaque materials. However, researchers from the Debye Institute of Nanomaterials Science and Tunte University have successfully improved the transmission of light through opaque materials by guiding light along specific paths. This may achieve better laser pointer light transmission properties through materials such as skin, and provide a better understanding. The researchers published their research results in the famous optical research journal "Optics Letters" in November this year.
Light diffusion is a phenomenon that occurs when light waves come into contact with objects with uneven surfaces or uneven structures. This diffusion makes it impossible to pass through things like skin, paper or clouds. These materials are largely opaque, and only a small portion of light can penetrate them. However, these materials do have open channels, that is, a certain kind of light can pass through the material path and light waves can follow, no matter how thick the material is. The research of doctoral students at Utrecht University has positioned these special paths through which light can pass through opaque materials.
In order to find out exactly how light is projected on matter, researchers use a method similar to "playing table tennis" to process light. "We send light in a random way, and then we use the light scattering data and send it along the same path in a slightly different way," Bosch explained. "In this way, more light can pass through the material." Repeating this process several times, the light passing through the material is sent back and forth, and the researchers discovered what kind of light wave must be there to make it pass through the material.
All light colors are different. The shape of the light wave front, that is, the front edge of the light wave, determines the degree of light penetration through the material. The best shape of the wave front of light waves of different colors is different. This principle is applicable to all wavelengths, but for each wavelength, only a single wavefront is in operation. If you determine the shape of the wavefront and then change the wavelength, you can see less and less light penetrating the material .
This understanding of the wavelength dependence of green laser pointer open channels provides researchers with a way to measure the "path length" of these open channels. How long has Light traveled along such a special road? The answer to this question provides an understanding of the transmission of light through scattering materials, which will be very useful for observing and penetrating such materials.