Self-regulated intensity noise dual-frequency laser using the buffer reservoir approach

Dual-frequency (DF) solid-state lasers provide very interesting characteristics for application in Radar-Lidar, metrology or microwave photonics systems. Indeed, such lasers sustaining the oscillation of two cross-polarized modes with different frequencies provide stable and tunable optically carried microwave beat-notes. Nevertheless, solid-state DF lasers suffer from resonant excess intensity noise due to their class-B dynamics. The introduction of a slight nonlinear absorption, such as two-photon absorption (TPA), inside the cavity of a single frequency laser has proved to be a powerful solution to cancel out the excess intensity noise at the laser relaxation oscillation frequency. By acting as a buffer reservoir (BR), the nonlinear losses deeply change the dynamical behavior of the laser leading to a self-regulation of its intensity. By proposing a new design intended to cancel out both in-phase and anti-phase excess noise, we tailor here the BR approach to solid-state DF lasers.