Nevertheless, our current theory suggests that measuring the τ c -dependence of k/k 0 could be the key to unraveling the fundamental mechanism in VSC. For example, under the strong coupling regime, if k/k 0 decreases as τ c increases, then the mechanism is likely to be kVSC in Eq. 17 with the disorder-enhanced local coupling theory . On the other hand, under the strong coupling condition Ω R,N ≫ τ -1 c , if k/k 0 increases as τ c increases, then it implies that under the single molecule level Ω R ≪ τ c , and the VSC mechanism is likely to be k VSC (Eq. 2 or Eq. 10) with a collective mechanism yet to be discovered. Experimentally, the cavity lifetime (or the quality factor) for the distributed Bragg reflector (DBR) FP cavity can be modified by changing the number of coating layers or the curvature of the mirrors . Other possible cavity structures that could achieve various Q factors are the "open" photonic structures , which might be more suitable for polaritonic chemistry than planar cavities, as these mirror-free open structures generally support lower quality photonic modes than the standard FP cavity design. In either case, experimental measurements on the cavity lifetime dependence of the rate constant will provide invaluable insights into the nature of the VSC effects.