Low-noise millimeter-wave synthesis from a dual-wavelength fiber Brillouin cavity.

In this Letter, a photonic system is proposed to generate millimeter waves with low phase noise and ultra-high frequency stability. By locking two free-running CW lasers to the same fiber cavity whose free-spectral range is actively stabilized, millimeter waves can be synthesized in a wide frequency range with fine-tuning capability. Exploiting the spectral narrowing effect of stimulated Brillouin scattering, the generated millimeter waves exhibit low phase noise that does not scale up as the frequency increases.