Dual focal-plane passive optical limiter for nanosecond pulses Available to Purchase

We describe optical limiters for nanosecond pulses based on a new cascaded-focus geometry. Nonlinear materials in the second focal plane provide low-energy limiting, while the nonlinear liquid CS₂ placed in the first focal plane provides a higher energy limiting threshold, to protect the material in the second focal plane from damage. The element in the second focal plane may be a reverse saturable absorber or a carbon black suspension (CBS) which exhibits nonlinear scattering. Using CBS, the limiter has a broad wavelength response, and clamps the maximum encircled output energy below 1 μJ for nanosecond and even longer pulses. The measured figure of merit of the device is approximately 20,000.