Two-frequency lasers: From excess quantum noise to RF photonics applications

We illustrate the physics of two-frequency lasers by two examples. The first example illustrates the fundamental consequences of the existence of two eigenstates on the laser line width. We indeed show experimentally that the non-orthogonality of these two eigenstates results in an increase in the laser quantum noise. We also give a physical explanation of this vectorial excess noise factor. The second example illustrates the capabilities of two-frequency lasers in terms of applications. In the domain of RF frequency generation by optical means, we show how a pulsed two-frequency source can be built for lidar-radar applications and pulsed RF frequency generation.