Both Japan and Germany attempted to develop DEW (Directed Energy Weapons) during WWII, and both reached the laboratory / prototype stage. Japan had in mind to use its microwave beams to literally turn off American bomber engines in mid-flight, whereas Germany appears to have intended its sound wave emitters for use against enemy troops, though there is also evidence of German DEW's that would have been used against aircraft had they been sufficiently powerful.
Japanese DEW's were tested against monkeys and they were strong enough to kill them at short range. Germany used other monkeys as passengers on V-2's and shot them into space. Wonder what the Axis had against monkeys?!?
From January 1945: Preliminary Report on Suspected Magnetic Ray. This was the result of a P-38 flying near a transmitter tower near Frankfurt of unknown type and experiencing engine and electrical system problems. The report was stamped Secret and produced by Headquarters, United States Strategic Air Forces Europe (Rear), Office of the Director of Intelligence. The Germans called this Motorstoppmittel. A document from June 1944 was titled Engine Interference by Electro-Magnetic Disturbances. It was subtitled: Project 1217, Investigation into German Possible Use of Rays to Neutralize Allied Aircraft Motors.
"In a Top Secret report entitled "Engine Interference Counter-Measures"
addressed to the Director, Air Technical Service Command, Wright
Field, Dayton, Ohio, reference was made to OSS discussions about a
German unit somewhere near Frankfurt/Main operating:
".....an influence interfering with conventional aircraft.....however
incredible it may appear to project from the ground to a height of
30,000 feet sufficient magnetic energy to interfere with the
functioning of the ignition system of an airplane, it must be
concluded that the enemy not only intends to interfere with our
aircraft by some immaterial means, but has also succeeded in
accomplishing this intention...."