Proton beam writing of dye doped polymer microlasers

Proton beam writing is employed to fabricate smooth sidewall whispering gallery mode microcavities in dye-doped polymer. These microcavities acts as microlasers under optical excitation in ambient atmosphere. Different cavity designs are implemented to obtain directional laser emission from the whispering gallery mode lasers. The microcavities are fabricated in Rhodamine B doped SU-8 polymer and are optically pumped with 532 nm pulsed laser. These microlasers emit light within the emission band of Rhodamine B with operational wavelength around 600 nm and the required pumping laser threshold is lower than 3 μJ/mm2 for all the micro-lasers.