Broad bandwidth THz pulse and e-beam characterization

Abstract

Electro-optic sampling (EOS) is widely used as a technique to measure THz-domain electric field pulses such as the self-fields of femtosecond electron beams. We present an EOS-based approach for single-shot spectral measurement that excels in simplicity (compatible with fiber integration) and bandwidth coverage (overcomes the laser bandwidth limitation), allowing few-fs electron beams or single-cycle THz pulses to be characterized with conventional picosecond probes. Experiments are conducted with a 0.11-THz-bandwidth optical probe and a broadband source (0-8 THz detection bandwidth) rich in spectral features. We observe clear optical sidebands for various electro-optic crystals. Sharp spectral features in the THz source spectrum are resolved. We also provide an outlook towards minimizing the crystal limitations and extending the detection bandwidth to 10's of THz. © 2012 American Institute of Physics.