LASER LABORATORY

The laser laboratory (Fig. 1) at the BMTI is part of the medical optics laboratory. For safety reasons, it is a separate room for laser applications. At the BMTI, lasers and laser diodes are used in a very broad power spectrum. Low-energy laser diodes (<1mW) of laser protection class 1 through to high-power lasers of laser protection class 3b (<3W) are used. They are used in the generation of point light sources, for example as the output point of spherical waves, as scanning beams in scanning laser ophthalmology (SLO) systems and for characterizing materials and material properties, among other things.

An optical phantom of the maternal abdomen during pregnancy is a suitable test environment for evaluating a non-invasive system for fetal pulse oximetry. Suitable materials and substances are required to replicate the optical properties of maternal tissue, fetal tissue and blood. For this purpose, phantoms made of transparent silicone or with water as the base material were produced. Cosmetic powders and ink were used as absorbing materials, while titanium dioxide particles were used as a scattering medium. Using an optical setup (Fig. 2) based on a white light laser (continuum laser) and collimation optics, defined transmission and reflection measurements in the spectral range of 600-900 nm were carried out on samples of artificial tissue using an integrating sphere and a radiospectrometer.