Measurements of detector nonlinearity at 193 nm.

We have developed a measurement system based on a correlation method to characterize the nonlinearity of a detector's response over a large range of laser pulse energy. The system consists of an excimer-laser source, beam-shaping optics, a beam splitter, a monitor detector, a set of optical filters, and the detector under test. Detector nonlinearities as large as 10% or greater over an entire measurement range at an excimer-laser wavelength of 193 nm are observed.