Lu Feng, Belkin Mikhail A
Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758, USA.
Opt Express. 2011 Oct 10;19(21):19942-7. doi: 10.1364/OE.19.019942.
We report a simple technique that allows obtaining mid-infrared absorption spectra with nanoscale spatial resolution under low-power illumination from tunable quantum cascade lasers. Light absorption is detected by measuring associated sample thermal expansion with an atomic force microscope. To detect minute thermal expansion we tune the repetition frequency of laser pulses in resonance with the mechanical frequency of the atomic force microscope cantilever. Spatial resolution of better than 50 nm is experimentally demonstrated.
我们报道了一种简单的技术，该技术能够在来自可调谐量子级联激光器的低功率照明下获得具有纳米级空间分辨率的中红外吸收光谱。通过使用原子力显微镜测量相关的样品热膨胀来检测光吸收。为了检测微小的热膨胀，我们将激光脉冲的重复频率调谐到与原子力显微镜悬臂的机械频率共振。实验证明了空间分辨率优于50纳米。
