We use simulations to investigate the interaction of ultra-intense laser pulses with a plasma. With an intensity greater than ${10}^{18}$ W/${\mathrm{cm}}^2$, these pulses have a pressure greater than ${10}^3$ M bar and drive the plasma relativistically. Hole boring by the light beam is a key feature of the interaction. We find substantial absorption into heated electrons with a characteristic temperature of order the pondermotive potential. Other effects include a dependence on the polarization of the incident light, strong magnetic field generation, and a period of intense instability generation in the underdense plasma.

• Received 2 March 1992

DOI:https://doi.org/10.1103/PhysRevLett.69.1383