Handbook of Biomedical Optics

751

35.1 Introduction

In 1967, a few years aer the rst working laser was invented,

Endre Mester in Hungary wanted to test if laser radiation might

cause cancer in mice (Mester et al. 1968). He shaved the dorsal

hair, divided them into two groups, and gave a laser treatment

with a low powered ruby laser (694 nm) to one group. ey did

not get cancer and to his surprise the hair on the treated group

grew back more quickly than the untreated group. is was the

rst demonstration of “laser biostimulation.” Since then, medi-

cal treatment with coherent light sources (lasers) or noncoherent

light sources consisting of ltered lamps or light-emitti ...