Microfabrication of optical resonators

Until recently, the laser was associated with an expensive device that required professional knowledge and appropriate technical facilities. Over time, semiconductor lasers have become popular, giving rise to telecommunications, information processing, diagnostic devices and entertainment. The laser from an exclusive device becomes more and more available and is used in other areas, from technology, through medicine, automotive, to everyday objects. Semiconductor lasers still require special conditions for their production, expensive equipment and specialized knowledge and skills.

Nowadays, we should strive to minimize the footprint of the production of devices, so we are looking for laser components that can be produced at low cost, with the use of polymers, or even better, natural materials. This would contribute to an even greater spread of lasers in everyday life.

In order to develop lasers, the methods of their production should be popularized. The main structure responsible for lasing is an optical resonator, in which the circulating light is amplified and generates a laser action. This structure could be produced with the help of the currently popular 3D printing, only in the micrometer scale. And this was the main goal of the project, the use of microfabrication techniques to produce optical resonators. For this purpose, the phenomena of nonlinear optics, in particular two-photon absorption and polymerization, were used, showing that 3D printing of optical resonators is feasible. The microfabrication process itself requires further research so that the obtained structures are able to generate a laser action with greater efficiency, thus increasing their usefulness.

At the same time, research was carried out on the use of natural materials in the light amplification, in particular proteins and sugar derivatives, as well as the use of multiphase systems. All activities carried out in the project were aimed at bringing closer the implementation of the optical sensor based on laser action. This was achieved by using cyclodextrins, compounds with a special structure, inside which it is possible to enclose other chemical compounds. Such an approach was applied for dyes, thanks to which we were able to precisely determine what aggregates are formed by the popular laser dye and how it affects the emission of light.

In this type of research, the experimental methods must be developed on a par with the theoretical studies in order to steer the experiments in a strictly defined direction. It also happened during this project, thanks to theoretical models of laser action, which were proposed to obtain laser action from distributed optical resonators.