Fibered luminescent concentrator: A bridge between flashlamp devices and laser technologies for skin therapy

Laser skin therapy and intense pulsed light (IPL) therapy are both light-based treatments used for various skin concerns. They have been used since decades and each system have their own specificity, advantages, and drawbacks. However specific treatment is still not accessible with standard techniques due to difficulties having a source with both laser and IPL advantages. We describe a new concept, the fibered luminescent concentrator-FLC, based on luminescent concentrators capable of concentrating spectrally and spatially an IPL source, resulting in a multi-color fibered device.

The FLC utilizes luminescent materials arranged in parallelepiped shapes polished on all faces. The IPL broadband spectrum is absorbed by the luminescent molecules and is re-emitted to a red shifted wavelength. The emitted spectral bandwidth ranges from green to dark red, depending on the type of luminescent concentrator. This light is then spatially concentrated by total internal reflections in the parallelepiped and guided through a fiber to the final operator.

We have developed three different solid luminescent concentrators based on a transparent polymer sheet (PMMA) doped with luminescent organic dye molecules for yellow and red emission, and an alexandrite crystal for emission in the dark red spectrum. We demonstrate that our new non-laser FLC device can concentrate spectrally and spatially the light with no temporal deformation and offers real opportunities for treatments where the IPL is less well-adapted.

The FLC is an additional tool for existing conventional systems such as laser or IPL sources. It is easily adaptable to any IPL source and is a very good complement, especially for wavelengths where the laser cannot easily produce light, such as the yellow band.