The Plasmonic Random Laser With Tuned Wavelength By A Mechanical Stretching Method

Three basic elements are required for laser emission: the pumping source of laser energy,the gain medium,the optical resonant cavity.The pumping source of laser energy and the gain medium of random laser are the same with traditional laser,while the resonant cavity is a lot of scattering particles,rather than the mirrors.This random laser has the advantages of good stability,small volume,low coherence,low directionality,low price,etc.It has great advantages and a wide range of applications in the laser display,lighting engineering,medical testing,special band,storage,document or material encoding mark,etc.In this paper,the research topic is focused on the followings.1.We fabricated the flexible plasmonic random laser samples embedded with gold nanoparticles.We studied the production of the plasmonic random laser with tuned wavelength which is made by gold nanoparticles,rhodamine 6G,vinylalcohol polymer,the random laser is pumped under different pump energy under the 532 nm pumped laser.Then we get the output wavelength is 591 nm,and the half peak width is from three to four nanometers.2.A tunable random laser is achieved by mechanical stretching experiments.When the sample is stretched,the random laser output wavelength appears blue shift phenomenon.When the sample is back to the original length,the random laser wavelength will return to the corresponding wavelength without stretching.When the sample is stretched 6 mm,the emission wavelength is shifted from 591 nm to 582 nm,and when the sample is back to the original length,the output is recovered to 591 nm.At the same time,it is found that the polarization state of the random laser can be changed by the stretching method.The polarization state is not obvious under the condition of the sample is not stretched,when the stretching direction is perpendicular to the polarization direction,the polarization is obvious,and the polarization is not so obvious when the direction of stretching is parallel to the polarization direction.3.We compared the properties of the samples without gold nanoparticles and doping gold nanoparticles.And the output wavelength which we have got is 591 nm,and the half peak width is three to four nanometers.The gold nanoparticles has a great influence on laser intensity and threshold.By using different polarizations of the pumping light,we demonstrated that both gold nanoparticles and rhodamine 6G have effect on the random laser blue shift.the blue shift phenomenon can also occur by stretching the wavelength when the sample is without gold nanoparticles.The intensity of random laser is consistent whether the sample is stretched or not.