Chen Ting-Hui, Huang Bing-Yau, Kuo Chie-Tong
Department of Physics, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
Department of Optometry, Shu-Zen Junior College of Medicine and Management, Kaohsiung 821, Taiwan.
Polymers (Basel). 2020 Apr 3;12(4):802. doi: 10.3390/polym12040802.
In this paper, a wavelength tunable colloidal-crystal laser with monodispersed silica particles was demonstrated. Silica particles were synthesized through the modified Stöber process and self-assembled into the colloidal photonic-crystal structure, which was then used to form the optic cavity of a wavelength tunable laser device. Due to Bragg's diffraction of the colloidal photonic-crystal and the coffee ring effect, the forbidden energy gap of light varied with different lattice sizes at different positions of the colloidal photonic-crystal. When the pumping pulsed laser irradiated on the gain medium of the sample, the fluorescence was restricted and enhanced by the colloidal photonic-crystal. Lasing emission with a single peak occurred when the energy of the pumping laser exceeded the threshold energy. The threshold energy and the full-width at half-maximum (FWHM) of the proposed laser were 7.63 µJ/pulse and 2.88 nm, respectively. Moreover, the lasing wavelength of the colloidal photonic-crystal laser could be tuned from 604 nm to 594 nm, corresponding to the various positions in the sample due to the coffee ring effect.
本文展示了一种基于单分散二氧化硅颗粒的波长可调谐胶体晶体激光器。通过改进的斯托伯法合成二氧化硅颗粒，并将其自组装成胶体光子晶体结构，该结构随后用于形成波长可调谐激光器件的光学腔。由于胶体光子晶体的布拉格衍射和咖啡环效应，胶体光子晶体不同位置处的光禁带能量随晶格尺寸的不同而变化。当泵浦脉冲激光照射到样品的增益介质上时，荧光受到胶体光子晶体的限制和增强。当泵浦激光的能量超过阈值能量时，会出现单峰激光发射。所提出的激光器的阈值能量和半高宽（FWHM）分别为7.63 μJ/脉冲和2.88 nm。此外，由于咖啡环效应，胶体光子晶体激光器的激光波长可以从604 nm调谐到594 nm，对应于样品中的不同位置。
