An inhibited laser

Traditional lasers function using resonant cavities, in which the round-trip optical path is exactly equal to an integer multiple of the intracavity wavelengths to constructively enhance the spontaneous emission rate. By taking advantage of the resonant cavity enhancement, the narrowest sub-10-mHz-linewidth laser and a 10^-16-fractional-frequency-stability superradiant active optical clock (AOC) have been achieved. However, never has a laser with atomic spontaneous radiation being destructively inhibited in an anti-resonant cavity where the atomic resonance is exactly between two adjacent cavity resonances been proven. Herein, we present the first demonstration of the inhibited stimulated emission, which is termed an inhibited laser. Compared with traditional superradiant AOCs exhibiting superiority for the high suppression of cavity noise in lasers, the effect of cavity pulling on the inhibited laser's frequency can be further suppressed by a factor of (2F/π)^2. This study of the inhibited laser will guide further development of superradiant AOCs with better stability, and may lead to new searches in the cavity quantum electrodynamics (QED) field.