A.V. Rzhanov Institute of Semiconductor Physics SB RAS, Prospect Lavrenteva 13, 630090 Novosibirsk, Russia. tsarev@.isp.nsc.ru
Opt Lett. 2011 Oct 1;36(19):3756-8. doi: 10.1364/OL.36.003756.
Fiber optic sensors are typically used with expensive tunable lasers or optical spectrum analyzers for wavelength interrogation. We propose to replace the tunable laser by a broadband optical source incorporated with a novel thin linewidth acousto-optic tunable filter. It utilizes optical beam expanders constituted by photonic crystal rows of air holes in LiNbO(3) waveguide. A new design is numerically studied for a short structure (with 32 photonic crystal rows) by a two-dimensional finite-difference time-domain method. Extrapolation of these results to larger structure sizes (about 1 cm) demonstrates the possibility to develop compact interrogators with 0.4 pm wavelength resolution and 40 nm tunable range around 1550 nm.
光纤传感器通常与昂贵的可调谐激光器或光谱分析仪一起用于波长检测。我们提出用一种新型的窄线宽声光可调滤波器代替可调谐激光器，该滤波器采用结合了宽带光源。它利用由 LiNbO(3) 波导中的空气孔光子晶体行构成的光学扩束器。通过二维有限差分时域方法对一个短结构（32 个光子晶体行）进行了数值研究。将这些结果外推到更大的结构尺寸（约 1 厘米）表明有可能开发出具有 0.4 pm 波长分辨率和 1550nm 附近 40nm 可调范围的紧凑型传感器。
