This paper describes the evolution of surface capillary waves of deep water excited by gradually increasing the lateral external force at a single frequency.The vertical velocities of the water surface are measured by using a Polytec Laser Vibrometer with a thin layer of aluminium powder scattering on the surface to reflect the laser beam.Nonlinear interaction processes result in a stationary Fourier spectrum of the vertical surface velocities(the same as the surface elevation),i.e.Iω～ω3.5.The observed spectrum can be interpreted as a wave-turbulent Kolmogorov spectrum for the case of 'narrowband pumping' for a direct cascade of energy.Correlation dimension analysis of the whole development process reveals four distinct stages during the wave structure development and identifies the wave turbulence stage.
