Yu Kan, Huang De-Xiu, Yin Juan-Juan, Bao Jia-Qi
Huazhong University of Science and Technology, Wenhua College, Wuhan 430074, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2013 Aug;33(8):2290-3.
Angle-tuned thin film filter is widely used in the DWDM system for its broad tunable wavelength range and high rectangular degree. The transmissivity and the half bandwidth is greatly influenced not only by the incident angle, but also by the wedge angle of the non-paralleled thin film filter. In the present paper, the influences of the wedge angle on the transmissivity and the half bandwidth were detailedly analyzed. The proper wedge angle and the orientation can greatly improve the characteristics of the transmittance spectrum. The angle-tuned thin film filter with 0.8 degrees wedge angle was also fabricated. The experimental results show that keeping the wedge angle with the same orientation to the incident angle will worsen the transmissivity and the rectangular degree of the transmittance spectrum. However, keeping the wedge angle orientation reverse to the incident angle will greatly enhance the transmissivity and the rectangular degree of the filter and its tunable wavelength range will broaden by 10 nm.
角度调谐薄膜滤波器因其宽可调波长范围和高矩形度而在密集波分复用（DWDM）系统中得到广泛应用。其透射率和半带宽不仅受到入射角的极大影响，还受到非平行薄膜滤波器楔角的影响。在本文中，详细分析了楔角对透射率和半带宽的影响。合适的楔角和取向可以极大地改善透射光谱特性。还制备了楔角为0.8度的角度调谐薄膜滤波器。实验结果表明，使楔角与入射角保持相同取向会使透射率和透射光谱的矩形度变差。然而，使楔角取向与入射角相反将极大地提高滤波器的透射率和矩形度，并且其可调波长范围将拓宽10纳米。
