ON-CHIP SCANNING CONFOCAL MICROSCOPE WITH 3D MEMS SCANNER AND VCSEL FEEDBACK DETECTION C. Gorecki, L. Nieradko et. al. Université de Franche-Comté, Besançon, FRANCE Wroclaw University of Technology, Wroclaw, Poland Transducers 07’ p 2561~2564 Au/ Reported by: Institute : 奈微所 Name : 楊志誠 Student ID : d9635804 VCSEL (Vertical Cavity Surface Emitting Lasers)

Outline Introduction Design and Fabrication Experimental & Simulation Results Conclusion

蔡司改良鏡片技術 光學顯微鏡從此 性能高強價格低廉 Microscope History 1665 虎克發明光學顯微鏡 1981~1986 賓尼等人發明STM, AFM 1886 蔡司改良鏡片技術 光學顯微鏡從此 性能高強價格低廉 2007 Now MEMS 1950 年代 TEM SEM 1957 Marvin 發明 Confocal TEM的電子束要能穿透切成薄片的標本， 通常用來研究細胞內部的超顯微結構 SEM 標本的表面先鍍上薄薄的一層黃金， 再用電子束掃瞄其表面，適合用來研究標本表面的微細結構 ，通常可以拍攝同一細胞表面的3D立體結構

Scanning Confocal Microscope Widely used in biomedicine, living cell Three-dimensional (3-D) image Non-invasive imaging of transparent samples 1.Reject light from out-of-focus planes 2.Provide clear in-focus image of a thin cross section http://www.microscopyu.com

Introduction Design and Fabrication Experimental & Simulation Results Conclusion

ARCHITECTURE OF CHIP-SCALE CONFOCAL MICROSCOPE 3 layers structure Comb-drive actuators (Z and X-Y) 100 μm for Vertical motion (Z) 50 μm in both directions by actuating of micro lens by x-y-axis scanner . Laser microscope on-chip silicon-based MEMS Glass micro lenses . VCSELs (Vertical Cavity Surface Emitting Lasers)

Fabrication process of glass microlens. [ Method 1] Isentropic Etching Glass reflow DRIE

Fabrication process of glass microlens [ Method 2] single-mask process KOH water solution<111> <100> Single-mask microfabrication of aspherical optics using KOH anisotropic etching of Si

Introduction Design and Fabrication Experimental & Simulation Results Conclusion

ANSYS Simulation Different shape design to investigate their performance Frequency and vibration [ High Displacement & Lower voltage ] [Higher Rigidity & Higher voltage ] for lens D > 300 μm

Glass microlens fabrication The silicon mould having depth from 46 μm to 90 μm Etch depth is non-linear function of mask diameter Etch rate 1.0-2.0 μm/min Mask Diameter & Mould Diameter are linear larger Microlens focal length Increased Etched time Silicon Nitride thicker

Introduction Design and Fabrication Experimental & SimulationResults Conclusion

Conclusion Precise positioning and focal tuning of micro lens — 2-3μm resolution — penetration depth down to 30 μ m Achieved high-resolution positioning control without need for large numbers of electrodes — 50 μm (X,Y) — 100 μm (Z) 500 times smaller than anything in this class

Discussion Wavelength of light used is major factor in resolution shorter wavelength  greater resolution Rayleigh criteria  refractive wavelength shorter，the penetration depth will be shallow。 Cell Damage : Cell damage and death for laser light Bleach：Most specimen without fluorescent，so adding dyes are necessary。 Laser light will bleach the dyes in the period of lighting。

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Reference [1] .Magnetically Actuated Scanning Microlens for NIR Raman Spectroscope , Chin-Pang- Billy Siu et al, MEMS 2007, Kobe , Japan, pp 735-738 [2]. S. Kwon and L.P. Lee, “Micromachined transmissive scanning confocal icroscope”, Optics Lett, vol. 29, pp. 706-709, 2004. [3] S Bargiel, L Nieradko, M Józwik, C Gorecki, J.A Dziuban, “New generation of fully integrated optical microscopes on-chip: application to confocal microscope“, Proc. SPIE, vol. 6186, 2006. [4] D. Heinis, C. Gorecki, “Feedback-induced voltage change of Vertical Cavity Surface Emitting Laser as an active detection system for miniature optical scanning probe microscopes”, Optics Express, vol. 14, pp. 3396-3405, 2006. [5] R. Carrasco, J.A. Dziuban, I. Moreno, C. Gorecki, R. Walczak, M. Kopytko, L. Nieradko, M. Józwik, “Optical microlenses for MOEMS” Proc. SPIE, vol. 5836, pp. 657-666, 2005. [6]. http://www.cyto.purdue.edu/flowcyt/educate/pptslide.htm [7]. www.cs.uky.edu/~jzhang/CS689/chapter7.pdf [8]. http://www.ntrc.itri.org.tw/dict/content.jsp

Vertical cavity surface emitted laser 面射型雷射二極體為一新型發光元件，此元件與傳統雷射二極體基本的差別在於 共振腔 磊晶層相對位置之不同；傳統雷射二極體的共振腔與磊晶層平行，反射面 係利用晶體自然斷裂面形成而與磊晶層垂直，雷射光由側面發出，故又稱邊射型雷射 (Edge-emitting laser)，而本元件的共振腔與磊晶層垂直，反射面係由磊晶層或表層 介電質薄膜組成，雷射光由正面發出，故稱為垂直共振腔面射型雷射。 邊射型雷射於晶片製程結束後須將晶片劈裂成晶條，並進行端面鍍膜，此製程複雜 耗時且為影響製程良率之關鍵。面射型雷射因非利用晶體自然斷裂面作為反射面，故 無須利用劈裂或進行端面鍍膜，可節省可觀之製程時間並避免因此而影響製程良率。 另於晶片製程結束後即可於晶片上直接進行元件量測(on wafer testing)，可節省量測 成本及時間。 預期面射型雷射可能之應用方向有下列各項： ‧光數據鏈路傳輸(Serial Optical Data Links)目前已有HP、Motorola、Honeywell、 IBM、Vixel等公司投入 ‧雷射列印(Laser Printing):利用面射型雷射則可同時二維列印，加快列印時間， 目前Xerox已投入此方面研究。 [工 業技術研究院 奈米科技研發中心] http://www.ntrc.itri.org.tw/dict/content.jsp

Rayleigh Criterion Definitions Acceptance angle θ Numerical Aperture NA = n sinθ Rayleigh resolution criterion for a circular aperture Δx = 0.61 λ/NA Highest Typical Resolution Optical Microscope ~200 nm Electron Microscope ~0.1 nm

Confocal Characteristics Tranditional Confocal Horizontal resolution (diffraction limited): Vertical resolution 共焦掃描顯微鏡僅對在聚焦面上形成清晰的影像，若我們逐步移動聚焦面，則可取得觀測樣品其深淺有序的斷面，將這些斷面的影像經由電腦處理，即可重組出相對應的三度空間影像。

Zeiss Confocal Microscope

Numerical Aperture

Sources of Aberrations Monochromatic Aberrations Spherical aberration Coma Astigmatism Flatness of field Distortion Chromatic Aberrations Longitudinal aberration Lateral aberration Images reproduced from: http://micro.magnet.fsu.edu/