Su tutmayan yüzey üzerinde duran mikrodamlacıklarda kontrollü deformasyon ve raman ışıması

Liquid microdroplets are ideally suited for applications that benefit from the properties of the whispering gallery modes (WGMs) because of their spherical shapes, smooth surfaces, biocompatibility, and flexible nature. In this thesis, we present nondegeneracy in WGMs as a result of deformation in the glycerol-water microdroplets using uniform electric field. Raman lasing from individual pure water microdroplets standing on a superhydrophobic surface is also presented in this thesis.A liquid microcavity provides relatively easy control of its shape due to its viscous and flexible nature. An applied external force, electric field, or control of the evaporation/condensation kinetics can change the shape of the liquid microdroplets. We demonstrated controlled lifting of the azimuthal degeneracy of the WGMs of glycerol water microdroplets standing on a superhydrophobic surface by using a uniform electric field. A good agreement was observed between the measured spectral positions of the nondegenerate WGMs. Our results revealed fewer azimuthal modes than expected from an ideal spherical microdroplet due to the truncation by the surface. We used this difference to estimate the contact angles of the microdroplets.Liquid microdroplets are also attractive in developing low threshold Raman lasers due to their high quality factors and small mode volumes. By using pure water microdroplets, we demonstrated Raman lasing near 650 nm. In the experiments, microdroplets were excited by a pulsed, frequency-doubled Nd:YAG laser at 532 nm. Intense laser emission was observed at frequencies corresponding to the WGM resonances of the water microdroplets near 650 nm where Raman resonances due to OH-stretching bonds of water are located. On-off behavior was observed during lasing and the average temporal inter-burst separation was determined from the time-dependent intensity traces.