诚信认证:
工商注册信息已核实!领域: | 细胞生物学,分子生物学,蛋白/抗体/蛋白质组,基因/基因组/测序,临床血液与检验学,分子诊断和芯片 | ||
样品: | gold nanobar fabricated on ITO | 项目: | 多频原子力激励与探测的方案实现 |
参考: | Physics Optics |
We theoretically and experimentally demonstrate a multifrequency excitation and detection scheme in apertureless near field optical microscopy, that exceeds current state of the art sensitivity and background suppression. By exciting the AFM tip at its two first flexural modes, and demodulating the detected signal at the harmonics of their sum, we extract a near field signal with a twofold improved sensitivity and deep sub-wavelength resolution, reaching λ=230. Furthermore, the method offers rich control over experimental degrees of freedom, expanding the parameter space for achieving complete optical background suppression. This approach breaks the ground for noninterferometric complete phase and amplitude retrieval of the near field signal, and is suitable for any multimodal excitation and higher harmonic demodulation.