Raman measurements of temperature during cw laser heating of silicon

We present the first Raman data from laser-heated silicon obtained in situ during the laser irradiation. Analysis of the Stokes to anti-Stokes ratios yields temperatures at the center of the laser spot which range from room temperature to the melting point as laser power is increased. The data agree well with the nonlinear heat diffusion calculations of Lax for Gaussian beam profiles when the temperature dependence of the silicon absorption coefficient is included. In addition, we show that analysis of the spectral profile of the Raman line can yield information on strain effects produced in the laser-heated spot.