ARTIFICIAL SPECTRAL BROADENING OF LASERS WITH RANDOM TELEGRAPH NOISE

Three methods are given for imposing random telegraph phase or frequen cy noise on a stabilized cw laser thus giving explicit control of the coherence of the laser field. In the case of phase noise, the resultin g laser spectrum consists of a carrier part with nearly Lorentzian sha ped noise sidebands which have full-width at half maximum up to 14 MHz . Complete suppression of the carrier is possible if the phase is made to jump by ir radians. Frequency telegraph noise results in a laser p ower spectrum that can be single or double peaked, depending on the re lative sizes of the average dwell time and the frequency jump. The las er field has been produced for studies of noise in nonlinear spectrosc opic interactions. Measurements of the resulting laser spectra are pre sented. As an example of the application of such a noisy laser, some r esults from studies of the dependence of two photon absorption on high er-order optical coherences are given.