Currently, there are wave beams / lasers / rays that operate from the X-Ray region to the Radio Wave region. Patents to create Gamma Ray beams / lasers / rays are also underway.
However, I have always wanted to see a device that can freely change the nature of the wave beam / laser / ray, such that the fired beam can be altered from Gamma Rays all the way to Radio Waves.
Such a concept stems from The Culture's main weapon, The Effector.
"An effector is a multi-purpose electro-magnetic manipulation device. Effectors were distant descendents of electronic countermeasure equipment employed by stage three civilizations.
Effectors may be used to manipulate machines and electronics. This may take the form of interfering with the machine's operations, disabling systems, or outright subversion and take-over.
Effectorized minds may not even consciously realize they are under attack. A machine may defend itself against effectorisation by quarantining or shutting down affected portions of itself. A final measure would be to use independent automatic subsystems to initiate a self-destruct rather than allow itself to be subverted.
Animal brains and nervous systems also suffer similar effects when effectorised. Effectorisation may cause pain and unconsciousness. Similarly, effectors may induce involuntary muscle action, which may be used for medical purposes.
Effectors may be used to kill biological life and melt equipment. They may also create auroras."
The effects seem mostly alright, except for the mind control of AI. Giving biological life pain, is mostly akin to microwave radiation.
Thus, I only ask if it is feasible to have a machine that alters the frequencies of the EM wave to change its nature, from Gamma Rays all the way to Radio Waves. With that, the photon beam can take form of any of the main 7 rays.
My only rules is no Handwave or major Unobtainium.