Continuously Tunable Optical Notch Filter With Functions of a Mirror and a Beam Splitter

IEEE Photonics Journal

卷:11

Mi-Yun Jeong¹  Keumcheol Kwak² 

[1] Department of Physics and Research Institute of Natural Science, Gyeongsang National University, Jinju, South Korea;

[2] School of Electronics and Electrical Engineering, Sungkyunkwan University, Suwon, South Korea;

关键词: Tunable optical filters;    continuous tunable filter;    liquid crystal filter;    optical devices;    photonic crystal;   

DOI  :  10.1109/JPHOT.2018.2885314

来源: DOAJ

【 摘 要 】

The objective of this study was to develop continuously tunable optical notch filters by combining four left- and right-handed circular cholesteric liquid crystal (CLC) cells without subsidiary optical components. By rotating each filter, the photonic band position could be continuously blue shifted over 100-nm spectral range. Using four notch filter sets with four different chiral dopant concentrations, spectral range from 440 to 870 nm could be covered. Since each CLC cell has only one chiral dopant concentration, it could be stable for a long time. Each filter is independent of polarization in the spectral range. Filter performance was highly enhanced by introducing an anti-reflection layer on the filter device. There was no light leakage inside the photonic band. Outside the band, transmittance was about 70%-100%. In addition, these filters had stable operation under extremely high laser intensity (~124 W/cm² of CW 532-nm diode laser and ~4.43 MW/cm² of Nd: YAG pulse laser operation for 2 h) without showing damage. Such filters also have functions as a mirror and a beam splitter. Depending on CLC materials, this simple and easy strategy could be used to prepare filters for applications in VIS and NIR spectral range devices.

【 授权许可】

Unknown