Second-order distributed feedback lasers based on films containing perylenediimide derivatives

Abstract

The fabrication and characterization of highly efficient and photostable second-order distributed feedback lasers (DFB), based on polystyrene films doped with a perylenediimide (PDI) derivative as active laser material, is reported. DFB gratings were obtained via thermal nanoimprint lithography and transferred to SiO₂ substrates by reactive ion etching. The influence of the PDI concentration on the laser performance has been investigated. The best results were obtained for the device based on the 0.5 wt% PDI-doped film, that emits at a wavelength of 571 nm, with a threshold of 2.5 μJ/pulse and a photostability halflife of around 500 min; i.e. 300000 pump pulses. The effectiveness of the DFB grating is evidenced by the decrease in threshold in two orders of magnitude with respect to the amplified spontaneous emission threshold obtained for a similar film deposited over a SiO₂ substrate without grating.