Microlight emitter on chip for information security applications

Abstract

This project utilized microfluidic technology to fabricate polystyrene (PS) droplets containing Nile Red dye. Following thermal concentration, droplets formed spherical optical cavities capable of laser excitation upon optical pumping. Injecting the PS spheres into a micro-well array allowed for their free distribution, forming a PS sphere array imbued with unique information, convertible into a laser-responsive QR code. Research revealed that the emission wavelength of PS spheres in the microarray was approximately 625 nm. Each unique emission center wavelength can serve as a distinctive identification for anti-counterfeiting labels. The QR code composed of PS spheres exhibited a degree of randomness, with optimal randomness observed at a 50% PS sphere filling rate. QR codes endowed with unique optical information can be fabricated into labels, integrated with product manufacturing, and hold potential for pivotal applications in the field of anti-counterfeiting.