The feasibility of utilizing the energetic capability of optical resonant cavities for new compound formation is examined with a positive conclusion. Unlike photochemical reactions which yield products which are thermodynamically stable in the absence of the cavity energy field, the present considerations are centered around compounds which are highly unstable under ordinary conditions. As specific examples the Group VIII-A hydrides are discussed, including their application as laser active media. Principal advantages of noble gas hydrides are lack of a bound ground electronic state (comparable with excimers), for less corrosiveness than Group VIII-A halides (or fluorine containing laser media), wide range of tunability including the soft X-ray/VUV region, and lack of decomposition of the compounds involved upon prolonged use (superior to dyes). Applicability of new laseers utilizing Group VIII-A hydrides is discussed, in relation to energy release (fusion) and metal-photon interaction problems.