Noise-immune cavity-enhanced optical heterodyne polarimeter: a novel scheme to explore left and right asymmetry in nature
Tzu-Ling Chen1*, Yi-Wei Liu1
1Department of physics, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:Chen Tzu-Ling,
Both chiral molecules and parity violation reveal the world about left and right asymmetry with a common phenomenon, optical rotation. In weak absorption region, however, detecting and quantifying it remains challenging.
In this work, a novel cavity-enhanced polarimeter is proposed to detect such small optical rotation. The polarimeter is based on a highly sensitivity spectroscopic method “NICE-OHMS (noise-immune cavity-enhanced optical heterodyne molecular spectroscopy)”.
In current status, a 1.28 μm quantum-dot laser based NICE-OHMS had been constructed using a high finesse cavity (F=18500). As a preliminary result, a minimum noise-equivalent absorption coefficient, αmin, 5.3×1010 cm-1Hz-1, had been reached with N₂O weak absorption lines.

Keywords: NICE-OHMS, Optical rotation, spectroscopy, high finesse cavity, frequency modulation