A Novel Method for The Fabrication of Fiber Lens and Its Application

• Main Authors: Yi-chien Lin, 林宜蒨
• Other Authors: Yung-chun Lee
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/42719738179365412428

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 96 === A single-mode fiber (SMF) with a microlens on one end is widely used as optoelectronic passive devices to facilitate laser-to-fiber coupling in optical communication systems. This thesis will apply the excimer laser planetary contour scanning method to fabricate refractive and aspheric microlenses which can be integrated with optical fibers. Two types of fiber lenses are investigated. The first one is for optic focusing aiming at a minimized focal spot size at a reasonable working distance.The second one is for optical collimation so that the beam coming out from the fiber has minimum divergence. Both types of fiber lenses can find a wide range of applications in electro-optic devices and optical communication. This thesis starts with the basic analysis on electromagnetic wave propagation in an optic fiber. Gaussian beam theory and the ABCD Law are then applied to characterized important parameters involved.Numerical analysis and optimization of the surface profiles of microlenses are carried out by ZEMAX. Finally, an KrF excimer laser micromachining system is utilized for the fabrication processes. The basic idea is based on a specific mask design method and a sample rotation method which includes both self-spinning and circular revolving to provide a probability function of laser machining. The probability function created by the planetary scanning assures a continuous, smooth,and precise surface profile to the machined microstructures. The surface profiles are measured and compared with their theoretical counterparts.Excellent agreements both in profile shapes and dimensions are achieved. The machining profile accuracy and surface smoothness of this proposed micromachining method show great potentials in fabricating micro-optic components.