Korean researchers are the first in the world to develop a new form of material that focuses energy while completely controlling the phase information of light.
 
SNU College of Engineering (Dean Cha Kook-Heon) states on 10^th that Department of Electrical and Computer Engineering Professor Park Namkyoo’s research team (Post-doctoral Researchers Yu Sunkyu and Piao Xianji) has created a design method of optical materials that enables the independent tailoring of intensity and phase of light.
 
In order to control the form of light (wave), the intervention of lens, magnifying glasses, or any appropriate substance (material) that can control the intensity and direction of light is mandatory. However, when light meets another object, the object alters the intensity and direction of light, which ripples to also change the phase of light. Thus, there is a limitation in transmitting information through light.
 
Hence, Professor Park’s team introduced a new perspective to resolve this issue by implementing interpretations of quantum phenomena. The team found parallels between their issue and the de Broglie-Bohm theory, an interpretation of quantum mechanics that 1929 Nobel Prize winner de-Broglie and theoretical physicist Bohm developed. Taking note of this theory, the team has succeeded in deriving a new optical formula that can regulate the intensity and phase information of light.
 
The first author of the research, Doctor Yu Sunkyu explains, “We first split the properties of optical materials to phase (classical Hamilton-Jacobi potential) and intensity (quantum potential). Then we separately manipulate the two parameters to combine them together later. (Please refer to Image 1.) As a result, the manipulation of phase at constant intensity (Left of Image 2) and confinement of light at constant phase (Right of Image 2) are possible.”
 
Likewise, the research team suggests a method to selectively fix either intensity or phase of light when light penetrates through an optical material. The findings of the research have practical value in that the design method allows the designing of material structure that produces designated wave intensity and phase. In addition, the need of a zero refractive index links the research to the field of metamaterial.
 
Professor Park states, “The team has proposed an innovative solution to an engineering problem of materials design by implementing an interpretation of quantum phenomena in physics into wave research. The implications of this research can stretch from the development of resonator that allows the transmission of phase information of incident light, the research on medical terahertz waves generated by optical rectification, to other fields in waves that involve sound waves or matter waves.
 
This research has been published on the prestigious journal of “Physical Review Letters” on May 10^th. It has been sponsored by the Global Frontier Projects (Center for Advanced Meta-Materials, CAMM) of the Ministry of Science and ICT, the Presidential Postdoctoral Fellowship Program of the Ministry of Education, the Korean Research Fellowship (KRF) of the Ministry of Science and ICT.

[Glossary]
1. Optical Medium: Material used to manipulate the propagation characteristics, direction, intensity, and phase of light
 
2. Optical Focusing: Phenomenon where light converges to a designated spot
 
3. de Broglie-Bohm Theory: Proposed by physicists de Broglie and Bohm, it interprets the quantum phenomena as an interaction between particles of known position and configuration with pilot waves. In contrast to the indeterminism of the Copenhagen interpretation, the de Broglie-Bohm theory allows the description of quantum phenomena to have deterministic trajectories. This study integrates this theory into its research by applying the Bohmian reformulation that separates classical and quantum potential to mathematical equations to achieve independent manipulation of optical phase evolution and energy confinement.
 
4. Terahertz Waves: The band covers the wavelength range of 0.3-3THz. It is widely used in medical fields and security inspections.