对于收集模式的近场光学显微镜,提出一种新的测量样品折射率和倾斜角的方法。这种方法中,使用一个反馈回路控制照射样品的光强,探针与样品保持等间距垂直振荡,照射样品的光有两束且位置对称。数字信号处理器控制照射光强改变、近场光强采样与探针振荡同步。在一个振荡周期获取一组近场光强极值,在另一个周期,改变每束光强度,隐失场分布发生改变,得到一组不同的近场光强极值,使用从多个振荡周期获取的不同近场光强极值,计算得到样品倾角,折射率。使用光栅和细胞膜对这种方法进行了测试,对光栅样品的扫描得到的形貌图显示这种方法横向分辨率优于400 nm,对细胞膜样品的测试显示细胞膜的折射率在1.4左右,从而表明这种方法不但能有效测量样品折射率,而且提供了一种使用光学信息构建样品形貌的新途径。

The rational design of the sample cell may improve the sensitivity of surface-enhanced Raman scattering (SERS) detection in a high degree. Finite difference time domain (FDTD) simulations of the configuration of Ag film-Ag particles illuminated by plane wave and evanescent wave are performed to provide physical insight for design of the sample cell. Numerical solutions indicate that the sample cell can provide more "hot spots'' and the massive field intensity enhancement occurs in these "hot spots''. More information on the nanometer character of the sample can be got because of gradient-field Raman (GFR) of evanescent wave.

AF/RSNOM is a new kind of scanning probe microscope developed in our lab, which is a combination of atomic force microscope and reflection scanning near field optical microscopy (AF/RSNOM) working in equi-amplitude tapping mode. This paper introduces the principle of AF/RSNOM and its advantages compared with other reflection mode scanning optical microscopes (RSNOM). Compared with the former RSNOM, this tapping mode AF/RSNOM has convenient operation and fewer background signals.

A new nano-meter scale resolution optical imaging mode and functional prototype of photon scanning tunneling microscope (PSTM) combined with atomic force microscope (AFM) named as AF/PSTM are introduced, and the advantages of AF/PSTM are discussed. Two separated optical images (refractive index image and transmissivity image) and two AFM images (topography image and phase image) of sample can be obtained during AF/PSTM's once scanning. AF/PSTM is applicable to all transmission samples in many fields, such as nano-biology, medicine, nano-optics, nano-industry, nano-science and technology, high-education and so on.

High signal-to-noise surface enhanced Raman scattering (SERS) signal of rat serum was obtained in this article. Two methods were presented to enhance the intensity of rat serum SERS signal. The novel colloid silver was synthesized using heating method by microwave and it was introduced to be the active site of SERS, "hot sites" could be detected in the active site. At same time the high numerical aperture (NA) oil immersed object lens was applied in micro-Raman system so that some new peaks come up in SERS spectrum of rat serum because of the evanescent wave was employed to excite the sample.

Optical trapping is an increasingly important technique for manipulating and probing matter ranging from nanometers to millimeters. In this paper, the theories of optical trapping to date are reviewed briefly. The typical conventional far field trapping design is introduced. A 5-micron yeast cell is trapped and manipulated with a 1.25 numerical aperture (NA) oil-immersion, 100X magnification objective by a 780 nm trapping beam at 16 mW in our experiment. Furthermore, the development of near-field optical trapping associated with evanescent wave is also discussed. Several proposed near-field trapping schemes, respectively using laser-illuminated metal tip, metal-coated fiber probe in the scanning near-field optical microscopy (SNOM) and focused evanescent wave, are also described.