Automatic Fiber Melting Cone Pulling Machine Based On The Characteristics Of The Cone Region Of The Melted Tapered Fiber

The fiber optic fused taper technology has extremely high application value in the preparation of fused taper type fiber optic devices such as tapered fibers and fiber couplers.During the preparation process of such devices,the optical fiber is usually heated by an external heating source.After the optical fiber enters the molten state,it is subjected to multi-directional displacement stretching operation through a three-dimensional displacement platform,causing the optical fiber to undergo morphological transformation and finally cooled and solidified.The fiber melting taper operation is the most critical step,which directly affects the performance of the prepared optical device.How to observe the shape and characteristics of the fiber optic taper in real-time through the equipment during the melting taper process,and carry out automatic control of the taper operation according to the characteristics of the taper shape is a difficulty in existing taper technology.In response to the above issues,this paper proposes a fiber optic melting and stretching machine based on the characteristics of cone shape changes during the fiber optic melting process,which is designed in software and hardware on the Xilinx ZYNQ platform.The equipment mainly includes image sensors,fiber optic fixtures,three-dimensional displacement platforms for motors,voltage drive boards,and other devices.In the field program gate array(FPGA)hardware part,design and integrate hardware modules such as optical fiber image acquisition,image preprocessing,direct memory access(DMA),image display,stepper motor drive and arc discharge drive.The fiber optic image acquisition module utilizes a complementary metal oxide semiconductor(CMOS)sensor and a light source to achieve the acquisition of high-resolution fiber optic image positions in three-dimensional space,The preprocessing module of fiber optic images performs noise reduction and optimization processing on fiber optic images,The image display module drives the display device for display,The motor drive module adjusts the speed and displacement of the stepper motor to achieve fiber optic taper control,The implementation of the arc discharge heating function driven by the arc discharge driving module.The software part of the Advanced RISC Machine(ARM)reads preprocessed image data from the FPGA hardware part for image recognition.Based on the actual fiber melting and taper operation,it realizes automatic displacement,cone area diameter detection,taper angle measurement,and other functions of the fiber.MFC is used to design the upper computer interaction interface,allowing the device to be controlled by the computer.After the equipment design is completed,the accuracy of the automatic displacement function of the optical fiber towards the heating area can be maintained within 3 pixels,and the calculation error of the diameter detection of the pulling cone area is within 5 μm,normally with 2 μm.And the measurement error of the pulling cone angle are within 6 °.The equipment can perform automated fiber optic melting and pulling cone operations based on the characteristics of the cone area.After simulating the fused tapered fiber using a theoretical model,the fiber fused tapered machine was used for the fiber fused tapered experiment.By adjusting the stretching length,taper speed,external voltage and other experimental parameters,it was found that when the taper length increased from100 μm to 800 μm,the decrease in light intensity is faster,and the length of the cone is 800 μm.When the light intensity decreases above m,the amplitude begins to slow down,and when the cone pulling speed is 200 μm/s.When the external discharge voltage is 10 V and the simulation results are closest,it can be concluded that the equipment has good preparation performance under this parameter and can meet the needs of laboratory preparation of tapered fiber.