Note: external multipass optical trap for counterpropagating pulsed laser applications

Pulses from a 12 mJ, frequency doubled, 5 ns FWHM, pulsed Nd:YAG laser were split and injected into opposing sides of a symmetric 2.44 m (96 in.) optical ring trap. Using a Pockels cell, the counterpropagating pulses were "locked" into the trap for ≥50 round trips. This optical trap has potential applications ranging from established cavity processes, e.g., laser-based absorption spectroscopy and x-ray production, to new processes such as non-resonant optical lattice gas heating and time-resolved coherent Rayleigh-Brillouin scattering diagnostic studies.