Design and optimization of dual-spot size optical systems for medical lasers

In this work we report on the development and optimization of a compact, single-handle, and multi-spot size laser system for medical hair removal, with the ability to change the output spot size from rectangular 24×32 mm² to elliptical 7×11 mm² while introducing minimal device size and energy loss. The design employs two sets of optical components to guide the laser beam and shape it to give users optimal output. The spot size change is achieved by utilizing opto-mechanical switch. The development of the system was carried out using industry-standard ray tracing code, to ensure the desired spot size and profile within the recommended work distance. Modeling results were corroborated by experimental implementation of the system in the lab with excellent results agreement. Energy losses were minimized by beam shaping and optimally designed apertures. Spot intensity calculations were conducted and modifications were applied to the system to avoid over exposure and to normalize the output power for both spot sizes. These results will be followed by a structural study aiming towards the development and design of the final product package.