Wide-band tunable photonic bandgap device and laser in dye-doped liquid crystal refilled cholesteric liquid crystal polymer template system
| Autor: | Chia Rong Lee, Jia De Lin, Guan Jhong Wei, Hong Lin Lin, Hsin Yu Lin |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Dye laser
Materials science Cholesteric liquid crystal business.industry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Laser 01 natural sciences Light scattering 0104 chemical sciences law.invention Optics law Liquid crystal Optoelectronics Photonics 0210 nano-technology business Luminescence Lasing threshold |
| Zdroj: | Emerging Liquid Crystal Technologies XII. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.2256839 |
| Popis: | The scientists in the field of liquid crystal (LC) have paid significant attention in the exploration of novel cholesteric LC (CLC) polymer template (simply called template) in recent years. The self-assembling nanostructural template with chirality can effectively overcome the limitation in the optical features of traditional CLCs, such as enhancement of reflectivity over 50%, multiple photonic bandgaps (PBGs), and changeable optical characteristics by flexibly replacing the refilling LC materials, and so on. This work fabricates two gradient-pitched CLC templates with two opposite handednesses, which are then merged as a spatially tunable and highly reflective CLC template sample. This sample can simultaneously reflect right- and left-circularly polarized lights and the tunable spectral range includes the entire visible region. By increasing the temperature of the template sample exceeding the clearing point of the refilling LC, the light scattering significantly decreases and the reflectance effectively increase to exceed 50% in the entire visible region. This device has a maximum reflectance over 85% and a wide-band spatial tunability in PBG between 400 nm and 800 nm which covers the entire visible region. Not only the sample can be employed as a wide-band spatially tunable filter, but also the system doping with two suitable laser dyes which emitted fluorescence can cover entire visible region can develop a low-threshold, mirror-less laser with a spatial tunability at spectral regions including blue to red region (from 484 nm to 634 nm) and simultaneous lasing emission of left- and right-circular polarizations. |
| Databáze: | OpenAIRE |
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