light frequencies and such

[kojikun]

anyone know if its possible to increase the frequency of light without producing those frequencies in the emitter?

for instance, in a discussion about FTL communication there was mention that the cesium vapor FTL pulse was group velocity, which would make the pulse frequency much greater then the two frequencies making it.

what im wondering is, does that pulse velocity have an increased frequency (i would think it does since the pulses are regularly spaced) and if so, would it be possible to use this wave property to produce high frequency pulses for trans-bluelight lasers for DVDs?