Highly stabile single mode and multi-mode random lasing emissions were observed from ZnO nanorods array prepared on glass substrates using chemical deposition technique. By varying the post-growth-annealing time, nanorod diameters between 54 and 78 nm with population densities between 75 and 95 nanorods/µm2 were obtained. Depending on the population density and diameter of the nanorods, single, double and triple random lasing emissions were observed with lowest threshold of 209 mJ/cm2. Furthermore, the lasing threshold showed an obvious dependency on the nanorods density. The lasing emission maintained its wavelength with increasing pump power, indicating high stability of the lasing mode(s).
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors acknowledge final year undergrads Wan Mohamad Hafiz Wan Mazlan and Natasha Liyana Hishammudin, under the supervision of WM and MNN, for preparing the samples. The authors would like to thank Professor Dr. Boon S. Ooi from KAUST for giving the opportunity to perform the random-lasing measurements in his laboratory (Photonics Laboratory). WM designed the experiment, did the optical measurements and drafted the manuscript. MKS did the lasing measurements and edited the manuscript. WM, MMH, MKS and MRH analysed the results. MNN prepared the sample and did the characterization measurements. All authors prepared the final manuscript. Partial funding from Universiti Sains Malaysia short term grant [304/PFIZIK/6312155] is greatly acknowledged.