Emission properties of femtosecond (fs) laser fabricated microstructures in Polystyrene (PS)

► We fabricated microstructures and diffraction gratings in polystyrene and observed emission from the fs laser modified regions. ► Fabrication of structures at lower energies (nJ) and higher scanning speeds lead to formation of luminescent micro-craters. ► Shift in the emission peak at different excitation wavelengths showed formation of several optical centers such as trans-stilbene, diphenylhexatriene (DPHT), and diphenylbutadiene (DPBD). ► The excitation spectrum by monitoring different emission wavelengths show similar spectrum.