Research on a method for on-line monitoring the power in microstructure fiber core based on machine vision

The special waveguide structure of microstructure fiber prevents the realization of high efficiency coupling connection, so the manufacture of couplers and process monitoring will become the key technology of production of fiber devices. In order to realize monitoring the light power in the fiber core and controlling the coupling ratio when the microstructure fiber is in the process of fused biconical taper, this paper puts forward a real-time monitoring method based on microscopic imaging technique and DSP technique, this method realizes the positioning of each fiber core and the measurement of output field´s optical power by using the CMOS camera with microscope to real-time monitor the optic fiber end and designing image processing algorithm about recording the most largest range of light, judging the characteristic region and data of normalization processing etc in FPGA and DSP, thereby the speed and the time of the fused biconical tapering fiber can be controlled. The results show that this method can complete the rapid detection of each fiber core´s optical power; the top treatment frame rate can reach 50 fps. This method also solves the problem of on line real-time monitoring during the fused tapering optical fiber well.