A research team led by Professor Hee-So No of the Department of Nanoelectronics and Physics, College of Science and Technology, Kookmin University (President Jeong Seung-ryul) has published a research paper titled “Inversely Designed Compact 12-Channel Mode Decomposition Spectrometer for On-Chip Photonics” in the latest issue of the SCI international academic journal ACS Photonics.

This research was conducted jointly by Professor Noh, Heeso and researcher Ji-Hoon Choi of the Department of Nanoelectronics and Physics at Kookmin University, Professor Koray Aydin of the Department of Physics at Northwestern University, and Professor Young-Ki Hong of Gyeongsang National University.

Spectrum analysis plays a very important role in characterizing light in optical systems. In particular, the miniaturization of spectrometers has been studied in various fields in on-chip photonics. However, conventional spectrographs have the drawback of being difficult to apply to optical integrated circuits. To overcome this limitation, methods that measure changes in light within the structure based on wavelength and reconstruct the incident spectrum through optimization have been actively studied.

Professor Noh Hee-so's research team at Kookmin University designed an ultra-compact mode spectrometer using Adjoint Solver inverse design. This allows light separated into multiple modes in the scattering region to be aligned and the original spectrum to be reconstructed. As a result, they have developed an ultra-compact on-chip spectrometer with high resolution.

Professor Noh stated, “Through this research, we have discovered the potential for designing and fabricating ultra-compact, high-resolution spectrometers that can be easily designed on-chip and manufactured using silicon processes. This is expected to contribute as an optical device for analyzing optical characteristics in next-generation optical integrated circuits.”