Study On The Fabrication Methods Of Plastic Optical Fiber Lantern

The research of cosmic ray detection technology allows people to explore the mysteries of the universe.Due to the low flow rate of high energy cosmic ray particles,and the effective area of the space detector is small,it can only be observed indirectly by ground mode.In ground detection technology,water Cherenkov detection,which combines the low energy threshold of the atmospheric Cherenkov telescope and the large field of view and high work cycle of the ground particle detector array,has been widely used in the field of cosmic ray detection.In recent years,plastic scintillating fibers have been found to be good sensitive devices for cosmic ray detection,but the attenuation of plastic scintillating fibers is very serious.If we can collect the light transmitted in the multiple plastic scintillation fiber with severe attenuation,and then use the white light fiber whose attenuation can be ignored for the long distance transmission of the light beam.The method is applied to the water Cherenkov detector,and the efficient detection of the cosmic ray can be achieved.In this paper,a plastic optical fiber lantern is put forward to insert a number of plastic fibers into the low refractive index plastic casing,and then the plastic fiber bundles are fused and taper.One end of the plastic fiber optic lantern is single,the other end is multiple,and the optical coupling from multiple plastic fibers to one plastic fiber can be realized.The theory of light transmission and optical mode coupling in conical fiber and fused taper fiber are analyzed,and the relationship between the transfer efficiency of light in the taper fiber and the cone angle and length is given.The LightTools software is used to simulate the plastic fiber and plastic optical fiber lanterns.A single plastic fiber with different taper and length is set up and the plastic fiber lanterns with different roots are compared.The taper area of the taper is not less than 0.2,otherwise the attenuation of the output intensity is more serious,and the length of the cone area is from 1 cm to 4 cm.The impact of the change is not very great.The above results are the theoretical basis for the follow-up experiment.On the basis of theoretical analysis,experimental verification is carried out.The taper experiment of plastic optical fiber and plastic fiber lantern is carried out by using the hydrogen oxygen flame device.The key is to control the temperature and time of heating.When the plastic fiber lantern is tapering,the constant rotation of the plastic fiber lanterns should be paid attention to,and the uniform heat of each surface is ensured.Two kinds of plastic optical fiber lanterns(4 and 7)are made in the experiments.The length of the cone is about 4cm,the waist is 1.5 mm(4)and 1.8 mm(7),respectively.The power transmission efficiency of the plastic fiber and plastic fiber lanterns after the taper is tested and the test experiments of the output light field are carried out.The light transmission efficiency of the plastic fiber lanterns made by the plastic fiber lanterns is 83.5%.