多模光纤耦合.pdfVIP

Page 1 of 8 ZEMAX Users Knowledge Base - /kb How to Model Coupling Into a Multi-Mode Fiber /kb/articles/141/1/How-to-Model-Coupling-Into-a-Multi-Mode- Fiber/Page1.html By Nam-Hyong Kim Published on 30 January 2007 This article demonstrates the use of the Geometrical Image Analysis feature to compute multi mode fiber coupling efficiency. The sample files can be downloaded from the last page of this article. Using Geometrical Image Analysis to Compute Multi-Mode Fiber Coupling Efficiency Coupling efficiency into multi-mode fiber can be calculated using the geometric image analysis feature. In order to use geometrical rays to model multi-mode fiber coupling, the fiber core diameter has to be at least 10 times larger than the wavelength, such that many transverse modes can be supported. If the fiber is multi-mode in the sense that two or three modes are supported, physical optics must be used. In this article, multi-mode is taken to mean that there are so many modes supported that the fiber can be treated as a light-pipe. The geometric image analysis can generate the irradiance at any surface, from an extended source with specific size and shape at the object surface. In addition, it can filter out rays that have larger incident angle than a definable threshold, at the evaluating surface. Using the attached sample file, we will demonstrate how to use the geometric image analysis feature to calculate multi-mode fiber coupling efficiency. Open the included sample file from the last page of this article. This file models coupling to a multi mode fiber with 0.1mm core radius and NA of 0.2. For now, we will ignore the Fresnel (reflection) losses from air-glass interfaces, including the fiber. mhtml:file://D:\我的文档\多模光纤耦合.mht 2010-3-15