Image-converter recording of picosecond pulses emitted by an erbium laser (λ=2.94 μ) with active mode locking

An image converter with a silver–oxygen–cesium photocathode (the red edge of the photoelectric effect was ~1.3 μ) was used to determine the time characteristics of single picosecond pulses emitted by an erbium laser at the fundamental frequency (2.94 μ) and at the second harmonic (1.47 μ). The duration of the photoresponse in the case of the fundamental-frequency pulses was 45 psec and the threshold sensitivity of the system was 10⁸ W/cm². It was found that the photoresponse of the image converter was strongly nonlinear.