Investigation On The Properties Of Energy Transmission And Spectral Characteristics In Dye Doped With Polymer Microfiber

As the most basic optical information transmission unit to realize the optical interconnection of photonic devices,micro-nano optical waveguides have become micro-nano photonics due to its strong optical field constraint,low energy loss,good light guiding ability,and convenient preparation process.One of the research hotspots in the field.This paper takes Rhodamine B（Rh-B）doped polymer microfibers（PMFs）as the research object,and systematically studies the beam transmission,fluorescence excitation and optical energy loss characteristics in PMFs..Based on the basic theory of light transmission in micro-nano optical waveguides,this paper designs basic experiments and fabricates micro-nano optical waveguides.The finite element method is used to simulate the energy distribution in the micron wires when light is coupled into a single PMF via the Si O₂ fiber nanocone.status.It is found that there is no obvious energy leakage on the surface of the microwire,and the light energy in the microwire is distributed in the form of sinusoidal periodic oscillation along the waveguide axis.Regarding the waveguide coupling excitation method,this article systematically compares the energy changes at the output end of the Rh-B doped PMF by measuring the gray value of the optical photo.It is found that the output end intensity（gray value）of the four groups of PMF with a diameter of 1.8μm and different doping concentrations decreases exponentially with the increase of the transmission distance.For PMF with different doping concentrations,the energy loss rate of the excitation light（532 nm）is 0.035 d B/μm（2.0 mg/g）,0.102 d B/μm（2.4 mg/g）,and0.083 d B/μm（2.8 mg/g）.g)and 0.063 d B/μm（3.2 mg/g）,the energy loss rate of Rh-B fluorescence（590～700 nm）is 0.018 d B/μm（2.0 mg/g）,0.036 d B/μm（2.4mg/g）),0.018 d B/μm（2.8 mg/g）and 0.016 d B/μm（3.2 mg/g）.The doping concentration with the highest proportion of fluorescence at the PMF output is 2.8mg/g,and the highest fluorescence output efficiency is 2.8 mg/g.This paper measures and analyzes the output spectral characteristics of a single Rh-B doped PMF.The results show that the Rh-B fluorescence envelope in PMF is in the 560-700 nm band,and it varies with the doping concentration.The energy loss of short wavelength is higher than that of long wavelength.When the doping concentration is 2.8 mg/g,the energy loss at 581.214 nm is 0.0323d B/μm,and the energy loss at 593.333 nm is 0.0147 d B/μm.And the blue shift degree of different concentration is different with the decrease of transmission length.When the concentration is 2.4 mg/g,the blue shift is from 593.3 nm to 582.1 nm,and when the concentration is 2.8 mg/g,the blue shift is smaller,from 588.8 nm to 585.3 nm.At3.2 mg/g,it is blue shifted from 588 nm to 581.2 nm.The energy loss of excitation light and fluorescence increases first and then decreases with the increase of concentration,which is consistent with the conclusion of the gray value method.In addition,a detailed comparison is made between the experimental structure and experimental results of the gray value method and the spectral situation,and the reasons for the difference in the results of the two methods are explained.The work in this paper provides a useful experimental basis for further improving the luminous efficiency of fluorescent dye-doped polymer micro-nano fiber devices and circuits,and reducing the power consumption of the devices.