Rapid Prototyping of Organic Linear Waveguides for Light Amplification Studies

Studying the luminescent properties and the light amplification capabilities are fundamental investigations for newly synthesized organic compounds intended to act as chromophores. These studies are conducted for compounds in the form of solutions, solids, and also molecules stabilized with the aid of polymers. One of the methods used to study amplification is the generation of amplified spontaneous emission (ASE) using stripe-shaped light beam excitation. This process can lead to the generation of ASE, but also, with the coexistence of microcrystals and scatterers, to the generation of laser action with random feedback, known as random lasing (RL). However, when the degree of light scattering is too high, it can lead to the inhibition of laser emission. Therefore, as an alternative in studying amplification properties, we developed a protocol that allows the investigation of laser action generation using rapidly prototyped polymer waveguides with an embedded dye. The setup used was based on Direct Laser Writing (DLW), which enables the controlled fabrication of multimode optical waveguides. We demonstrated that the use of this technique will allow for the study of the performance of dyes from strictly structured resonators, enabling measurements of gain and lasing threshold. This allowed us to lower the lasing thresholds while maintaining the directionality of emission.