傳統的光纖式近場光學顯微鏡受到截止效應、熱傷害等問題影響，造成解析度有所限制，因此可開發無孔徑的近場光學掃描式顯微鏡(apertureless near-field scanning optical microscope，aNSOM)來突破。其原理主要藉著原子力顯微鏡(atomic force microscope，AFM)的探針與入射光場作用，產生區域電場強化的效應，與樣品作用後產生一有效散射場。論文主要的研究是以AFM為基礎，研製一套aNSOM，期望其光學空間解析度可達到10nm以下，並將其應用於螢光樣品的影像量測。
研發之aNSOM由於其收光的顯微物鏡位於遠場偵測干涉後的高頻干涉信號，其信號包含針尖與奈米結構作用後的近場光學信號及遠場的背景雜訊，為了增加影像的訊噪比(signal-to-noise ratio，SNR)，利用距離調變技術且搭配自差式干涉(homodyne interferometry)與外差式干涉(heterodyne interferometry)系統擷取信號；其中外差式干涉技術多引入一道可控之參考信號，對於影像之SNR之提昇比自差式干涉更有效。另外，論文中也針對近場螢光影像作相關之討論與量測，並分析探針與螢光分子的電場交互作用及螢光信號的擷取，期望未來可將本系統應用於分子生物學，得到分子尺度的醫學螢光影像。

The optical spatial resolution of conventional aperture near-field scanning optical microscopy is limited by cut-off effect and thermal noise effects. An apertureless near-field scanning optical microscope (aNSOM) has been developed to break the limitation. The localized electromagnetic field near the region between the sample and the tapping tip of atomic force microscopy (AFM), and then the effective scattering field which including near-field optical signal will be detected by far-field microscopy. This thesis attempts to develop an aNSOM based on a commercial AFM to achieve an optical spatial resolution better than 10 nm. Furthermore, the aNSOM is applied to measure near-field fluorescence signal
In the system, the modulated optical signal including the near-field signal and background noise is collected by a far-field microscope. In order to improve the near-field image with a high signal-to-noise ratio (SNR), the signal from the tapping tip at high harmonic terms is demodulated for both homodyne and heterodyne interferometric detections. With the help of an addition reference signal, the heterodyne detection can improve the SNR by rejecting near-field background noise. To test the system performance, a near-field fluorescent image from fluorescence molecules is grabbed. The interaction between the fluorescence signal and the tip is studied to assist how to obtain the fluorescent signal more efficiency. Eventually, the system could play a key role in biomolecular field, and provide fluorescence image with a molecular -scale resolution.

[1] Y. Inouye and S. Kawata, “Near-field scanning optical microscope with a metallic probe tip,” Opt. Lett. 19, 159-161 (1994).
[2] R. Bachelot, P. Gleyzes, and A. C. Boccara,“Near-field optical micro- scope based on perturbation of diffraction spot,”Opt. Lett. 20, 1924-1926 (1995).
[3] D. Courjon, Near-Field Microscopy and Near-Field Optics, Imperial College, London (2003).
[4] R. C. Dunn,“Near-Field Scanning Optical Microscopy,”Chem. Rev. 99, 2891-2927 (1999).
[5] F. J. Giessibl,“Advances in atomic force microscopy,”Rev. Mod. Phys. 75, 949-983 (2003).
[6] K. Dickmann, J. Jersch, and F. Demming, “Focusing of laser radiation in the near-field of a tip (FOLANT) for applications in nanostructuring,”Surf. Inter. Anal. 25, 500-504 (1997).
[7] S. Nie and S. R. Emory,“Probing signal molecules and single nano- particles by surface-enhanced Raman scattering,”Science 275, 1102 (1997).
[8] B. Pettinger, G. Picardi, R. Schuster, and G. Ertl,“Surface-enhanced and STM tip-enhanced Raman spectroscopy of CN- ions at gold surfaces,” Electroanal. Chem. 554-555, 293-299 (2003).
[9] M. S. Anderson,“Locally enhanced Raman spectroscopy with an atomic force microscope,”Appl. Phys. Lett. 76, 3130-3132 (2000).
[10] R. M. Stockle, Y. D. Suh, V. Deckert, and R. Zenobi,“Nanoscale chemical analysis by tip-enhanced Raman spectroscopy,”Chem. Phys. Lett. 318, 131-136 (2000).
[11] N. Hayazawa, Y. Inouye, Z. Sekkat, and S. kawata,“Metallized tip amplification of near-field Raman scattering,”Opt. Comm. 183, 333-336 (2000).
[12] M. Fleischmann, P. J. Hendra, and A. J. McQuillan,“Raman spectra of pyridine adsorbed at a silver electrode,”Chem. Phys. Lett. 26, 163-166 (1974).
[13] D. L. Jeanmaire and R. P. V. Duyne,“Surface raman spectroelectro- chemistry: Part I. Heterocyclic, aromatic, and aliphatic amines adsorbed on the anodized silver electrode,”Electroanal. Chem. 84, 1-20 (1977).
[14] 黃貞翰，探針強化近場掃描式光學顯微鏡之研製，國立成功大學工程科學研究所，九十五學年度碩士論文。
[15] A. Bek, Apertureless SNOM: A New Tool for Nano-Optics, PhD. thesis, Bilkent University (2004).
[16] B. Knoll, F. Keilmann, A. Kramerm, and R. Guckenberger,“Contrast of microwave near-field microscopy,”Appl. Phys. Lett. 70, 2667-2669 (1997).
[17] B. Valeur, Molecular Fluorescence Principles and Applications, Weinheim, Wiley-VCH, New York (2002)
[18] G. G. Stokes, “On the change of Refrangibility of Light,” Philosoph. Trans. Roy. Soc. of London, 142, 463-562 (1852).
[19] G. Lessard, Apertureless Near-Field Microscopy for Fluorescence Imaging, PhD Thesis, California Institute of Technology (2003).
[20] E. J. Sanchez, L. Novotny, and X. S. Xie, “Near-Field Fluorescence Microscopy Based on Two-Photon Excitation with Metal Tips,” Phys. Rev. Lett. 82, 4014-4017 (1999).
[21] L. T. Nieman, G. M. Krampert, and R. E. Martinez,“An apertureless near-field scanning optical microscope and its application to surface-enhanced Raman spectroscopy and multiphoton fluorescence imaging,” Rev. Sci. Instrum. 72, 1691-1699 (2001).
[22] Y. S. Barash, Van der Waals Forces, Nauka, Moscow (1988).
[23] M. S. Jean, S. Hudlet, C. Guthmann, and J. Berger, “Van der Waals and capacitive forces in atomic force microscopies,” Appl. Phys. 86, 5245-5248 (1999).
[24] H. Raether, Surface Plasmons on Smooth and Rough Surfaces and on Grating, Springer-Verlag, New York (1998).
[25] 蘇園登，表面電漿共振相位影像系統，國立中央大學機械工程研究所，九十三學年度碩士論文。
[26] 吳民耀、劉威志，“表面電漿子理論與模擬”，物理雙月刊，28，486-496 (2006)。
[27] A. Bouhelier, M. R. Beversluis, and L. Novotny, “Near-field scattering of longitudinal fields,” Appl. Phys. Lett. 82, 4596-4598 (2003).
[28] B. Knoll and F. Keilmann, “Enhanced dielectric contrast in scattering- type scanning near-field optical microscopy,” Opt. Comm. 182, 321-328 (2000).
[29] J. L. Bohn, D. J. Nesbitt, and A. Gallagher, “Field enhancement in apertureless near-field scanning optical microscopy,” Opt. Soc. Am. A 18, 2998-3006 (2001).
[30] L. Aigouy, A. Lahrech, S. Gresillon, H. Cory, A. C. Boccara, and J. C. Rovoal, “Polarization effects in apertureless scanning near-field optical microscopy: an experimental study,” Opt. Lett. 24, 187-189 (1999).
[31] S. Kawata and V. M. Shalaev ed., Tip Enhancement, Elsevier, Oxford (2007).
[32] D. Mehtani, N Lee, R. D. Hartschuh, A. Kisliuk, M. D. Foster, A. P. Sokolov, F. Cajko, and I. Tsukerman,“Optical properties and enhance- ment factors of the tips for apertureless near-field optics,” Opt. A:Pure Appl. Opt. 8, 183-190 (2006).
[33] J. T. Krug, E. J. Sanchez, and X. S. Xie, “Design of near-field optical probes with optimal field enhancement by finite difference time domain electromagnetic simulation,” Chem. Phys. 116, 10895-10901 (2002).
[34] 莊錦和，無孔徑型掃描式近場光學顯微鏡之調變訊號分析，國立成功大學機械工程所，九十六學年度博士論文。
[35] P. G. Gucciardi, G. Bachelier, S. J. Stranick, and M. Allegrini, Applied Scanning Probe Method VIII: Scanning Probe Microscopy Techniques, Springer, Berlin Heideberg, 1-29 (2007).
[36] L. Gomez, R. Bachelot, A. Bouhelier, G. P. Wiederrecht, S.-H. Zhang, S. K. Gray, H. Feng, S. Jeon, J. A. Rogers, M. E. Castro, S. Blaize, I. Stefanon, G. Lerondel, and P. Royer, “ Apertureless scanning near-field optical microscopy: a comparison between homodyne and heterodyne approaches,” Opt. Soc. Am. B 23, 823-833 (2006).
[37] P. G. Gucciardi, G. Bachelier, and M. Allegrini, “Far-field background suppression in tip-modulated apertureless near-field optical microscopy,” Appl. Phys. 99, 124309 (2006).
[38] J. W. Lichtman and J. A. Conshello, “Fluorescence microscopy,” Nat. Meth. 2, 910-919 (2005).
[39] http://micro.magnet.fsu.edu/primer/techniques/fluorescenceintro.html.
[40] 駱文，董成淵，“台大物理系顯微生物物理實驗室之現況與展望”，物理雙月刊，24，455-461 (2001)。
[41] H. F. Hamann, M. Kuno, A. Gallagher, and D. J. Nesbitt, “Molecular fluorescence in the vicinity of a nanoscopic probe,” Chem. Phys. 114, 8596-8509 (2001).
[42] J. T. Krug, E. J. Sanchez, and X. S. Xie, “Fluorescence quenching in tip-enhanced nonlinear optical microscopy,” Appl. Phys. Lett. 86, 233102 (2005).
[43] R. X. Bain, R. C. Dunn, and X. S. Xie, “Single Molecule Emission Characteristics in Near-Field Microscopy,” Phys. Rev. Lett. 75, 4772-4775 (1995).
[44] A. Fragola and L. Aigouy, “Fluorescence apertureless scanning near- field microscopy for high resolution biological imaging,” Proc. SPIE 5143, 139-143 (2003).
[45] http://www.ntmdt.com/.
[46] 林正祥，光電訊號處理系統於生醫檢測之開發與應用，國立中央大學機械工程研究所，九十四學年度碩士論文。
[47] 遠坂俊昭原著，宋國明譯，PLL電路設計及應用，全華科技圖書股份有限公司，(2006)。
[48] B. Hecht, H. Bielefeldt, Y. Inouye, D. W. Pohl, and L. Novotny, “Facts and artifacts in near-field optical microscopy,” Appl. Phys. 81, 2492-2498 (1997).
[49] C.-H. Chuang and Y.-L. Lo, ”An analysis of heterodyne signals in apertureless scanning near-field optical microscopy,” Opt. Exp. 16, 17982-18003 (2008).