Park Sang-Jun, Lim Ji-Hun, Lee Yong-Hoon, Kim Inbo, Cho Jinhang, Rim Sunghwan, Choi Muhan
Opt Express. 2021 Mar 15;29(6):9242-9251. doi: 10.1364/OE.417744.
It was reported that whispering gallery cavities designed by conformal transformation optics can support high-Q resonant modes with emission directionality. Intrinsically, these cavities have gradient index profiles implementing conformal mappings in physical space. In this paper, using the linear coordinate transformation, we propose another design scheme of whispering gallery cavities with (piecewise-) homogeneous, anisotropic index profile. We numerically show that so-designed cavities are also able to support high-Q whispering gallery modes with directional far-field emission patterns. We verify such characteristics by using a phase space representation (called the Poincaré Husimi function) of the intracavity wave function.
据报道，通过共形变换光学设计的回音壁腔可以支持具有发射方向性的高Q共振模式。本质上，这些腔具有在物理空间中实现共形映射的梯度折射率分布。在本文中，我们利用线性坐标变换，提出了另一种具有（分段）均匀、各向异性折射率分布的回音壁腔设计方案。我们通过数值计算表明，如此设计的腔也能够支持具有定向远场发射模式的高Q回音壁模式。我们通过使用腔内波函数的相空间表示（称为庞加莱胡西米函数）来验证这些特性。
