- Applicable in cutting-edge optics, such as in high-capacity optical communication and quantum information communication (published in Nature Photonics)
The Ministry of Science and ICT (Minister Lee Jong Ho, hereinafter referred to as "MSIT") announced that a research team led by Professor Park Hong-Gyu at Seoul National University, through joint research with Professor Yuri Kivshar's team at Australian National University, has successfully developed technology for ultra-small, high-quality nanolaser.
This research was conducted under the MSIT's Basic Research in Science and Engineering Project (Mid-career Researcher Program). Its results have been published* in the international academic journal "Nature Photonics" on November 28th (November 27th, 16:00 in local time, GMT).
* Article title: Vortex nanolaser based on a photonic disclination cavity
Recently, active research is being advanced in the field of optics to find ways to control the characteristics of light. In particular, manipulating the angular momentum of light assumes various applications, for example, high-capacity optical communication. Thus, many researchers focused their attention in developing devices that amplify light, known as lasers.
For this reason, conventional laser devices were often combined with a filter that imparts specific angular momentum to light. However, this approach had limitations, most notably its large size exceeding several tens of micrometers[㎛], and their suboptimal performance.
On the other hand, ultra-small laser devices exhibited excellent performance, but lacked capacity to possess angular momentum. The need for completely different approach departing from previously reported studies arose as a result.
The research team drew inspiration from the similarity between the formulas describing electrons and light, respectively in condensed matter physics and optics. They devised a creative method of designing photonic insulator* required for laser devices, discovering the key to solve the problem.
* Photonic insulator: A device confining unique resonant modes of light to implement laser beams
The research team developed a new laser structure called the "photonic disclination* cavity" by placing air holes into the atomic sites within an artificially created crystal, and succeeded in implementing a vortex nanolaser where the light emitted from the laser device rotates in a clockwise (or counterclockwise) direction.
* Disclination: A kind of disruption found in crystalized atomic structures
To experimentally validate this design, the research team produced the newly developed photonic insulator with disclination cavities on a semiconductor substrate and observed the laser light, and confirmed the identification of orbital angular momentum in optical vortices.
The size of the photonic insulator developed by the research team is 3.75 times smaller than those reported in previous studies, while efficiency of the laser device has increased by 24 times.
According to Prof. Park Hong-Gyu, the significance of this research lies in the development of a novel laser structure, photonic disclination cavity, and that it introduced for the first time the ultra-small vortex nanolaser. He stated, "This new nanolaser allows for precise control of polarization characteristics as well as other characteristics of light, making it highly valuable for further research in high-density photon/quantum integrated circuits."
For further information, please contact the Public Relations Division (Phone: +82-44-202-4034, E-mail: msitmedia@korea.kr) of the Ministry of Science and ICT.
Please refer to the attached PDF.