Calculation Method for the Geometric Dimensions of a Scanning Near-Field Optical Microscope Optical Fiber Probe and Experimental Verification

CSME 2019/12
Volume 40 No.6 : 557-570

Calculation Method for the Geometric Dimensions of a Scanning Near-Field Optical Microscope Optical Fiber Probe and Experimental Verification

Zone-Ching Lin^a and Ming-Ho Chou^b
^aDepartment of Mechanical Engineering, National Taiwan University of Science and Technology, No.43, Keelung Rd., Sec.4, Da'an Dist., Taipei City 10607, Taiwan
^bDepartment of Vehicle Engineering, National Army Academy,, No.750, 3rd Neighborhood, Longdong Rd., Zhongli City, Taoyuan City 32093, Taiwan (R.O.C.)

Abstract: This study proposes an innovative calculation method for the geometric dimensions of a scanning near-field optical microscope (SNOM) optical fiber probe. We employ molecular mechanics and vibration theory to construct a simulative measuring model of a SNOM. We use a complex Boolean operation to arrange the probe and the sample atom-by-atom and then establish an atomic model for the simulative measuring model of SNOM. We conduct a scanning electron microscopy (SEM) photographing experiment to measure the geometric dimensions of the probe and then draw a relational diagram of the geometric dimensions and deduce their relational equations. We also find the potential energy parameter values of the Morse potential energy model among different atoms in order to solve the problem of the unknown potential energy parameter value by using the Lorenz—Berthelot mixing rule. We combine the optimal search of the Levenberg—Marquardt method with a reasona-ble convergence criterion to acquire the optimal geometric dimensions. In addition, a SNOM optical fiber probe is used to compare the results of the experimental and simulative measurements.

Keywords: SNOM, optical fiber probe, simulative measurement, geometric dimension

Download PDF

*Corresponding author; e-mail: zclin@mail.ntust.edu.tw

TOP