Title :
Sol-gel ZnO-SiO2 composite waveguide ultraviolet lasers
Author :
Leong, Eunice S P ; Chong, M.K. ; Yu, S.F. ; Pita, K.
Author_Institution :
Sch. of Electr. & Electron. Eng., Nanyang Technol. Univ., Singapore, Singapore
Abstract :
Random laser action with coherent feedback is realized in ZnO-SiO2 composite films, which consists of ZnO clusters embedded in SiO2 dielectric matrix prepared by sol-gel technique. The films are deposited on silicon substrate with a SiO2 buffer layer to form a waveguide structure. Ultraviolet lasing at room temperature is observed from the composite films with ZnO : SiO2 molar ratio varying between 1 : 5 and 1 : 30. The corresponding lasing wavelength and linewidth under 355-nm optical excitation are found to be ∼388 nm and less than 0.6 nm, respectively. Our experiment has shown that the proper control of light confinement inside the random cavities leads to coherent random lasing.
Keywords :
composite materials; dielectric materials; laser cavity resonators; laser feedback; light coherence; optical films; optical pumping; silicon compounds; sol-gel processing; solid lasers; spectral line breadth; ultraviolet sources; waveguide lasers; wide band gap semiconductors; zinc compounds; 355 nm; 388 nm; SiO2 buffer layer; SiO2 dielectric matrix; ZnO clusters; ZnO-SiO2; ZnO-SiO2 composite; coherent feedback; coherent random lasing; composite films; lasing linewidth; light confinement; optical excitation; random cavities; random laser action; room temperature; silicon substrate; sol-gel technique; ultraviolet lasers; ultraviolet lasing; waveguide lasers; Buffer layers; Dielectric substrates; Laser feedback; Optical films; Optical waveguides; Semiconductor films; Silicon; Temperature; Transmission line matrix methods; Zinc oxide;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2004.834914
