Physical and engineering advances offer more effective methods than the technologies available today to reduce the phenomenon of light reflection.

When a ray of light passes from one medium to another, although both are transparent (from air to glass), some light intensity is reflected and some pass through. This phenomenon is a general phenomenon of wave propagation, which is reflected in the reflection we see when looking out the window into the dark, and also exists in radio waves, microwaves, sound waves, and pressure waves. Even wave activity describing quantum particles.

“Different media have different optical properties due to the phenomenon of partial reflection,” said Prof. Kobe Schuer explains. “For example, the speed of light in the air and glass is different due to the partial reflection of the window glass – the light in the glass progresses more slowly. The echo phenomenon we hear near the rocks is similar.

A new study suggests an innovative method of eliminating the reflection of light waves from surfaces, which prevents the reflection of a wide range of wavelengths or frequencies. The study was led by Prof. Kobe Schuer and Prof. Powell Ginsberg Ivy and Elder Fleischmann from the School of Electrical Engineering at the Faculty of EngineeringDr. of the Institute of Physics and Technology in Moscow. In collaboration with Dmitry Pilonov, it was recently published in the popular journal Optics Express.

Disable the interfering component

In most cases, the researchers note that the phenomenon of partial repetition is a disruptive factor. In complex observation and optics systems such as microscopes, the partial reflection phenomenon can significantly reduce the intensity of light reaching the human eye or detector and significantly affect system performance. To solve the partial return phenomenon at a broad frequency, the researchers approached the problem from a completely different direction.

Prof. Schuer expands: “In general, an ‘anti-reflection coating’ can be used to reduce the effect of partial reflection.” Such coatings can be found in a wide variety of optical and acoustic. Systems, and even spectacles, the main drawback of this method is its limited efficiency, it is suitable for a single frequency, and it is a resonant frequency. “

In systems that need to handle wavelengths or frequencies, such as glasses or microscopes, the current method does not completely eliminate partial reflection of light. In principle, this method can be extended to handle a range of wavelengths or frequencies by combining a coating consisting of several layers of different materials and thicknesses, but the design of multi-layer coatings is very difficult due to the complex optimization of the layer thickness. And properties required.

Glad to see you: “Resonance with white light”

To overcome the limitations of the current methods, the researchers developed a device known as a “white light resonator”. Prof. According to Schuer, “unlike the standard resonators, which have a fixed and finite number of resonant frequencies, the concept behind the new resonator is to use differentiations to create the destructive interference of the reflected waves across the entire resonator’s range. It is possible to realize a special resonator for the integration of several layers, but unlike the traditional approach, the design does not require simple and complex computerized optimization.

The researchers tested the validity of the concept by implementing a structure that eliminates a wide range of frequencies in the microwave range, through the realization of a white light resonator consisting of segments of waveguides with selected properties accordingly. To control the characteristics of the segments that make up the resonator, the researchers filled them with meta-materials identified using three-dimensional printing.

Prof. Schuer concludes with optimism: “The concept of white light resonance is universal and can be applied to all types of waves and all frequency ranges.

To the scientific paper

More about the topic on the Knowledge website: