GaN Ultraviolet Laser based on Bound States in the Continuum (BIC)
GaN Ultraviolet Laser based on Bound States in the Continuum (BIC)
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DOI：
10.1002/adom.202201906
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发表时间：
2023-01
影响因子：
9
通讯作者：
Mu-Hsin Chen;Di Xing;V. Su;Yang-Chun Lee;Y. Ho;J. Delaunay
中科院分区：
文献类型：
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作者：
Mu-Hsin Chen;Di Xing;V. Su;Yang-Chun Lee;Y. Ho;J. Delaunay
连续介质中的光学束缚态(BICs)实现了对面外辐射损耗的实质性抑制，被用来实现强光限制和高品质因数(Q)的光学模式。基于光学BIC模式的窄线宽激光效应在近红外和可见光范围内已被证实，但在紫外(UV)区域的BIC激光器尚未见报道。由于具有紫外光波长的光源在各个领域都是必不可少的，基于高Q模和定向发射的紧凑型紫外光激光器的设计策略是非常必要的。在此，通过在GaN薄膜上设计一维周期抗蚀剂结构，展示了第一个基于BIC的紫外区激光器。利用对称保护的BIC模式，制作的激光器具有定向单模激光发射，半高宽为0.10 nm，发散角为1.5°。观察到了与结构边长相对应的周期性结构区域的激光作用。此外，通过改变周期和温度来实现对紫外激光的波长控制。这项工作为设计占地面积小、窄线宽和面外发射的紫外光激光器提供了策略。
Optical bound states in the continuum (BICs), realizing substantial suppression of out‐of‐plane radiative losses, have been utilized to realize strong light confinement and optical modes with high quality‐factor (Q). Lasing actions with narrow linewidths based on optical BIC modes have been demonstrated in the near‐infrared and the visible ranges, but BIC‐based lasers in the ultraviolet (UV) region have not been reported. As light sources possessing wavelengths at the UV scale are essential in various fields, the strategy to design compact UV lasers based on high‐Q modes and directional emissions is highly desirable. Here, the first BIC‐based laser in the UV region is demonstrated by designing a 1D periodic resist structure on top of a GaN film. Using the symmetric‐protected BIC mode, the fabricated laser is having a directional single‐mode lasing emission with a small full‐width at half‐maximum of 0.10 nm and beam divergence of 1.5°. The lasing action is observed with a periodic structure area corresponding to a structure side length as small as 8 µm. Moreover, the wavelength control of the UV lasing is achieved by varying the period and temperature. This work provides strategies to design UV lasers having a small footprint together with narrow‐linewidth and out‐of‐plane emissions.