  Low-contrast all-optical Zeno switching has been demonstrated in a silicon
nitride microdisk resonator coupled to a hot atomic vapor. The device is based
on the suppression of the field build-up within a microcavity due to
non-degenerate two-photon absorption. This experiment used one beam in a
resonator and one in free-space due to limitations related to device physics.
These results suggest that a similar scheme with both beams resonant in the
cavity would correspond to input power levels near 20 nW.
