Preparation Of Combined-beam Fiber Probe And Its Application In Fluorescence Testing

Fluorescence spectroscopy is an important testing technology widely used in industry,agriculture,life science,environmental science,materials science,food science and public safety and many other fields.In recent years,fiber-optic probe-based fluorescence testing methods have become a research hotspot.This method has the advantages of high efficiency,microscopic,real-time,in-situ,integrated,miniaturized and portable.In this paper,three kinds of fiber-optic fluorescent probes are designed based on fiber-optic light guiding theory.Three kinds of fiber-optic probes are prepared based on CO₂ laser welding machine.The active optical fiber preforms and rare earth doped ceramic materials are tested.Fluorescence spectroscopy,several factors affecting the fluorescence intensity are analyzed,and the application of the spatial distribution of fluorescence spectra of various materials is realized,which meet the design requirements of fiber probes.In the simulation and design of fiber-optic fluorescent probes,a reflective fiber-optic fluorescent probe is proposed.One end of the fiber-optic probe is coupled to the light source and the other end is coupled to the receiving fiber.The fiber optic fluorescent probe is simulated by Matlab.It is concluded that the intensity of the fluorescent signal that can be received by the receiving fiber is affected by the core diameter,NA and core-package ratio of the fiber.Therefore,when making the fiber optic fluorescence probe,the fiber with a large numerical aperture and a large core packet ratio is preferred.In the preparation of optical fiber fluorescent probes,the key technology is a combiner consisting of a pump fiber and N receiving fluorescent fibers.Based on the theory of fiber-optic combiner manufacturing,three types of fiber-optic fluorescent probes of 125?m7×1,4×1 and 3×1 combiners are prepared by using a new type of carbon dioxide laser welding machine LZM-100.In the fluorescence test of fiber-optic fluorescent probes,the test platform is built based on the Omni-?500 grating spectrometer.By comparing several sets of fluorescence tests of rare earth doped materials,the following conclusions can be drawn:as the distance between the needle of the fiber optic probe and the surface of the sample increases,the fluorescence line strength of the sample gradually weakens.The signal-to-noise ratio of the fluorescence spectrum measured by the 7×1 fiber probe is larger than that of the 3×1 fiber probe,and the fluorescence receiving efficiency of the 7×1 fiber probe is higher than that of the 3×1 fiber optic probe.In a certain power range,the fluorescence intensity increases with the increase of the pump optical power.When the power continues to increase,the saturation effect and thermal effect will make the fluorescence intensity of the sample become lower.The fiber probe and displacement platform test the fluorescence spectra of rare earth doped ceramic materials and fiber preform sections at different positions,which visually shows the spatial distribution of rare earth ions.