Measurement Of Hollow Optical Fiber Using Image Processing Techniques

The paper presents a method of geometric measurement of hollow-core optical fiber using the image processing techniques. It is proposed especially for the hollow-core optical fibers, considering the defect of the present meas- urement techniques.First, the paper introduces the basic knowledge of the image processing technique, emphasizes the image processing method that is used in the measur- ement System, Such as edge detection operator, Curve fitting algorithm, espe- cially Hough change in detail, etc.Second, the paper introduces the VC++6.0 program language, analyses its peculiarity and advantage, explains the form of the image in the computer and DIB visiting functions.One end face of optical fiber sample sets on the carring-table of the micr- oscope is observed, selecting appropriate amplification, afterwards, take a ph- otograph with a CCD camera, then the picture was sent to the computer by the photograph-gathering card. The image is processed with a software automatic- ally, so this method can reduce artificial errors.The technique adds greatly to the accuracy of the measurement by accum- ulating data over the entire boundary rather than just two cuts. The method also has the desirable feature of time saving and operator bias removing. The technique can be applied for the measurement of the outside diameter, the core diameter, or the core concentricity of hollow-core optical fibers, so as to eval- uate fibers. The entire measurement, including the regulation of the image clear and precise, is completed within 5 min with a reproducibility that can be as high as 5 micrometer for good fiber samples.