Hyeonjae Kim

Absorption Spectroscopy

Atomic spectroscopy

This study presents a methodology for measuring the buffer gas pressure inside atomic vapor cells and monitoring the alkali atom number density through linear absorption spectroscopy measurements and theoretical calculations.

Linear absorption spectroscopy in rubidium vapor cells: Applications in buffer gas measurement and lifetime estimation

Buffer Gas Pressure Estimation for OPAMs

Rubidium Vapor Cell Lifetime Monitoring and Analysis Tool

Aging

Aging test of atomic vapor cells

This study evaluated the long-term stability of cubic glass atomic vapor cells through high-temperature aging tests. Furthermore, it presented the first quantitative demonstration that introducing an Al2O3 coating on the inner walls of the cubic glass atomic vapor cells can reduce rubidium consumption and contribute to lifetime extension.

Aging test of atomic vapor cell Al2O3 wall coating on cubic glass

Lifetime extension of Rubidium vapor cells by Al2O3 coating

OPM

Optically Pumped Atomic Magenetometer (OPAM)

This research analyzes various physical phenomena arising from atomic–light interactions within an optically pumped magnetometer (OPM), using both theoretical modeling and experimental measurements. In particular, we aim to realize the spin-exchange relaxation-free (SERF) regime and use the resulting setup to study magnetic noise sources. These efforts support the development of low-SWaP (size, weight, and power) OPMs suitable for practical sensing applications.

Towards the development of a SERF magnetometer

MiliTECH_2023

Semiconductor quantum dot-optical fiber connection study for wired quantum cryptography communication

May. 2023 - Nov. 2023

Engaged at Quantum & Nanobio Photonics (QNP) Lab (Prof. Yong-Hoon Cho), Department of Physics, KAIST

Awarded 2nd Prize (Agency for Defense Development Director General’s Award) at the 2023 Militech Challenge hosted by KAIST

MiliTECH_2022

Design of air-land quadrotor using hemisphere shell passive wheel

May. 2022 - Nov. 2022

Engaged at Aerospace Systems and Control Lab (ASCL, Prof. Hyochoong Bang), Department of Aerospace Engineering, KAIST

Awarded 2nd Prize (Korea Military Academy President's Award) at the 2022 Militech Challenge hosted by KAIST

NANO_internship

Fabrication of a flexible photo-electrochemical cell using laser processing

Jun. 2021 - Jun. 2022

Engaged at Novel Applied Nano Optics (NANO) Lab (Prof. Junyeob Yeo), Department of Physics, Kyungpook National University (KNU)

Awarded 3rd Prize of Academic Conference hosted by the College of National Sciences, KNU