High refractive-index microspheres of optical cavity structure

Abstract

Microspheres of refractive index of nD>2 have been investigated. The organic-inorganic hybrid microspheres of refractive index nD=1.70–1.72 were prepared at room temperature by the vibrating orifice technique using titanium alkoxide and silane coupling reagents as starting materials. Subsequently heating the microspheres at 400–450 °C resulted in increasing their refractive indices to nD=2.10–2.25 with keeping good spherical shape. Rhodamine 6G-doped microspheres of nD=1.72 were also prepared at room temperature and the lasing from them was performed by pumping by second-harmonic pulses of Q-switched Nd–yttritium–aluminum–garnet laser.