A modulated cavity including a cavity; a modulation source; and a modulator
located with said cavity and in electrical communication with said
modulation source. The modulation source overdrives the modulator with a
period of modulation T.sub.mod substantially equal to T.sub.roundtrip
(n+(p/q)).sup.-1. n, p, and q are integers. T.sub.roundtrip is the period
of a pulse making one round-trip in the cavity. In one embodiment of the
invention p and q are relatively prime. In another embodiment of the
invention the optical response of the modulator includes the qth harmonic
of (1/T.sub.mod). In yet another embodiment of the invention p/q is an
integer. In still yet another embodiment of the invention p/q is a
rational number.
