Using three spectrometers power calibrated by NIST calibration light sources, the optical powers and spectra over the 20 nm to 800 nm region were absolutely determined on hydrated silver shots caused to detonate with a low-voltage, high current pulses. Continuum high-energy, extreme ultraviolet (EUV), radiation at megawatt average and 10-megawatt peak power levels were observed. The EUV spectrum matched theoretical predictions for the electronic transition of a hydrogen atom to the hydrino atomic state with a quantum number of ¼ catalyzed by nascent HOH. The input energy was determined by eliminating the detonation-produced electromagnetic pulse with a shunt resistor. (Recent synchronous calorimetric and wall power measurements validated this approach link.) There is no other explanation for the observed optical energy output of about 30 times the input wherein (i) no energy releasing conventional chemical reaction was possible, (ii) the radiation was predominantly 100 times more energetic than possible under the applied low-voltage condition, and (iii) the radiation comprised unprecedented megawatt-level continuum light with most of the radiation in the short wavelengths.