Аннотация:Dynamics of refractive index variation in diamond crystal during and after its irradiation by fs laser pulses has been investigated by the pump-probe interferometric technique. It is found that, as well as the positive +Delta n variation of refractive index determined by the Kerr effect and the negative -Delta n resulting from bulk ionization, there is a positive +Delta n determined by material heating. Analysis of experimental data and modeling allows us to visualize a laser heated volume, to trace its growth in time and to determine the temperature of material in the beam waist. The maximum observed temperature for intensity approximate to 3 x 10(12) W cm(-2) is estimated as 700 K.