Abstract

We present the first practical optical limiter for ultrashort, ~ 100-fs, laser pulses. Optical limiters show decreased transmittance with increasing laser pulse energy so that the transmitted energy is kept small.¹ These devices are characterized by the onset-of-limiting energy E_on (pulse energy at which the transmittance T has fallen to T_lin/2,T_lin transmittance in the linear regime), the “dynamic range” = E_D/E_on (E_D damage energy), and the maximum transmitted output energy E_max. A practical device for the protection of the human eye or sensitive photodetectors combines a low E_on with a high dynamic range, small E_max, and a large linear transmittance. With our concept, a low threshold E_on = 11 nJ, a large dynamic range of 10750, and sufficient linear transmittance T_lin = 28% are obtained. Moreover, the transmitted energy E_max is restricted to 1.3 μJ.

© 2002 Optical Society of America