A thermo-optic switch is operated in a novel near-impulse mode in which the drive pulse width is shorter than twice the diffusion time of the switch. The drive pulse width is less than the rise time of the steady-state optical response and also less than the rise time of the deflection efficiency response to the applied drive pulse. The drive pulse can further include a sustaining segment following the initial short pulse segment, if it is desired to maintain the switch in an ON state for a longer period of time. A number of additional techniques are described for further reducing the response time of the switch. An array of thermo-optic switches operated in this manner can form a display which, due to the fast individual switch rise times, can operate at an overall fast refresh rate.