The laser beat wave programs at Rutherford Appleton Laboratory and Ecole Polytechnique are reviewed. The techniques used to generate by multiphoton ionization the highly uniform plasmas needed for the beat wave are described. Evidence of the generation of a 2% plasma wave using laser beams at 1.064 and 1.053 μm is presented. The plasma wave suffers damping, possibly by the modulational instability. The use of a high-power short laser pulse for plasma-wave generation by the wake-field process is discussed. This process has the advantage that there is no resonance as in the beat wave, and since the plasma wave is generated on the time scale of the plasma period, instabilities are unlikely to be important.