泄漏辐射模显微镜测量薄膜的局域双折射率

Local Birefringence of Anisotropic Film Measured by Leaky Radiation-Mode Microscope

介质双折射率的传统测量方法有偏振光椭圆率测量仪和光学相干断层扫描等。提出一种新型的介质双折射率测量方法——切向偏振光照明的泄漏辐射模显微镜激励波导模共振,通过对物镜后焦面的傅里叶光谱信息进行成像,测量介质的双折射率。分析了利用切向偏振光照明的泄漏辐射模显微镜测量介质双折射率的原理并测量了双折射率差为Δn≈0.005的偶氮聚合物薄膜的光致双折射效应,该方法可实现高灵敏度、高空间分辨率的双折射率测量。

There are several methods for birefringence measurement such as ellipsometer and optical coherence tomography.A novel method for birefringence measurement is proposed.The waveguide-mode resonance is excited by leaky radiation-mode microscope with azimuthally polarized beam illumination.By observe the Fourier spectrum on back focal plane,the birefringence character can be measured.The principle of birefringence measurement with this method is analyzed and the photo-induced birefringence about Δn≈0.005 of azobenzene（AZO） polymer film is measured,which can achieve high sensitivity and high spatial resolution birefringence measurement.