Diamond-like films were prepared by laser ion beam deposition technique

and the optical absorption

photoluminescence and the dependence of photoluminescence on incident light intensity were measured. Our experimental results indicate that optical gaps vary in the range of 1.67-2.25eV

and the photoluminescance spectrum is a broad band with peak position in the range of visible light. The facts that superlinear luminescence photooxcited by lower incident light intensity and linear luminescencs photoexcited by higher incident light intensity have been explained in terms of the model of nongeminate radiative recombination. Using the model of tail state saturation we also illustrate the fact of blue shift of photoluminescence paak position when increasing the incident light intensity.