Abstract CO 2 laser-induced decomposition of liquid hexamethyldisiloxane (Me 3Si) 2O with graphite sensitization has been studied. Suspended graphite is used for an effective heterogeneous sensitization due to very efficient absorption of CO 2 laser radiation. In the experiments the laser line 10P16 ( ∼948 cm −1 ) coinciding with the absorption minimum of the a ν Si– O band ( 1055 cm −1 ) of (Me 3Si) 2O is selected for irradiation. This choice allows to avoid radiation losses due to low (5.4×10 −4 Torr −1 cm −1) vapor absorption and to ensure the maximum (>100 μm) penetration depth of the laser radiation into the liquid. The decomposition is a thermal process and can be denoted as pulsed laser thermolysis. A thermodynamic approach is proposed to evaluate the temperature of graphite particles and adjacent liquid layers resulting from the laser pulse heating. It is shown that for a 100 ns laser pulse at fluence of 1 J/ cm 2 adjacent liquid layers with a thickness of 0.2 μm can be heated to temperatures in the range of 400–800 ° C . The high (>8 MPa) pressure inside the supercritical liquid layers favors the decomposition. The IR, mass analyses of irradiated liquid samples indicate the formation of linear polystructures as decomposition products.