<title>Ultrafast Picosecond Chronography</title>

Abstract

The electron-optical streak camera is one of the few instruments capable of directly measuring a picosecond optical signal both linearly and in real time. The goal of this research has been the development of a synchronously operating streak camera system suit-able for use with mode-locked dye laser sources. The major accomplishments of this research are threefold: 1) A complete single-event streak camera system was constructed. The laser source was a mode-locked dye laser and amplifier system producing picosecond pulses with gigawatt powers. The camera was based on a Photochron II streak tube and microchannel plate intensifier. An optical Multichannel Analyzer was used to generate a real-time digital and graphic representation of the picosecond optical event. The system provides a powerful tool for future research in picosecond high excitation and nonlinear processes. 2) A synchronously operating streak camera system was constructed for use with an actively mode-locked R6G dye laser producing tunable picosecond pulses at a repetition rate of 82 MHz. The streak camera was operated at the laser repetition rate by employing a sinusoidal high-voltage RF deflection signal. The high data-accumulation rate was shown to yield a substantial increase in sensitivity and dynamic range over conventional single-event streak cameras. Time resolution was ≈25 ps and appeared to be limited by laser jitter rather than by the streak camera technical time resolution. 3) The viability of the synchronous streak camera for picosecond spectroscopy of solids was demonstrated by performing the first direct time-resolved measurement of bound exciton luminescence in CuCl. Single crystals at 8°K were excited by the frequency-doubled dye laser. The lifetime of the bound exciton of I line was typically ≈130 ps with a formation time of ≈ 10 ps. Excellent signal-to-noise ratios were obtained with excitation energies even as low as 10^-13 J per pulse.