This invention relates to cleaning compositions comprising unsaturated fluorinated hydrocarbons. The present invention requires an equilibrium cracking catalyst composition comprises at least one Y-type zeolite having kinetic conversion activity of at least about 3 in combination with a Lewis acid containing alumina composite present in at least 50 weight percent of the composition. To achieve this target, the invention proposes that by means of a beam splitter part of the light coupled out of the optical resonator is passed on to an optical delay line and coupled back into the optical resonator upon having passed through the optical delay line.