Atomic interference in a microchip laser operating on a Lambda transition

In a LiNdP4O12 microchip laser pumped by a diode laser, atomic interference arise due to the simultaneous oscillation on two transitions forming a Lam bda configuration. For a microchip laser, the low-frequency coherence is an important dynamical variable. It is coupled to the low spatial frequency o f the population inversion grating. This results in modal intensities which are self-pulsing while the total intensity remains nearly constant. In add ition, the modal power spectra display combinations of the relaxation oscil lation frequencies which are absent in the power spectrum of the total outp ut power.