  By cryogenically cooling the Yb:YAG/Cr:YAG medium, one can break through the
damage limit of Yb:YAG/Cr:YAG passively Q-switched microchip lasers at room
temperature and thus achieve a shorter minimum pulse duration. In the proof of
principle experiment we carried out, a 160.6 ps pulse duration was obtained. To
the best of our knowledge, this is the first realization of sub-200 ps pulse
operation for an Yb:YAG/Cr:YAG microchip laser
