Using Two-Photon Photoemission for Auto Correlation Measurement
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
Lasers are capable of producing pulses of such short duration that their intensity as a function of time cannot be measured directly by usual electronic devices. The technique of determining the autocorrelation of the laser pulse by means of nonlinear mixing of the pulse with a delayed replica of itself can overcome that problem. Presently, the most widely used method for this purpose is second-harmonic generation in a nonlinear crystal. In this scheme, the energy of the second-harmonic radiation is recorded as a function of the delay time between the two copies of the laser pulse. The phenomenon of two- photon photoemission has been frequently observed, as first presented by H. Sonnenberg, H. Heffner, and W. Spicer (Appl Phys . Lett . 5, 95 (1964)).