High-Performance Characterization of Photocathode Excitation Pulses

The fundamental limiting factor limiting Free Electron Lasers brightness is the electron source, or photoinjector. Next generation X-ray Free Electron Lasers and electron instruments will strongly depend on the breakthrough advances in electron sources. One possible solution to improve brightness is to use specifically shaped ultraviolet pulses to excite the photocathode in order to shape the electron cloud properly for injection into the accelerator. Ultraviolet spatio-temporal ultrafast pulse measurement is needed to develop the needed pulse shapes. In this SBIR/STTR, we will develop new methods for temporal and spatio-temporal measurement of ultraviolet ultrafast laser pulses to support the development of laser pumped ultra-bright electron sources. These techniques need to provide the dynamic range and have the signal-to-noise ratios needed to provide the guidance needed to properly shape the photocathode driving pulses. In Phase I, we will demonstrate the feasibility of our proposed techniques for temporal and spatio- temporal measurement of deep UV ultrafast laser pulses. Dynamic range and sensitivity will be examined as well as the accuracy and precision of the techniques. Our ultraviolet ultrafast laser pulse measurement technology will provide badly needed diagnostics in commercial markets. Deep ultraviolet ultrafast pulses are used in both scientific instruments and the semiconductor industry. This SBIR project will also develop new technologies for telecommunications applications.