Laser frequency standards at the P N Lebedev Physical Institute

A brief review is made of the investigations conducted at the Laboratory of Frequency Standards at the P N Lebedev Physical Institute (FIAN) Division of Quantum Radiophysics along an important line of inquiry into the development of quantum frequency standards—the elaboration of a subminiature clock based on the coherent population trapping effect in alkali metal atoms with semiconductor laser pumping (frequency stability of 10⁻¹¹–10⁻¹² for an averaging time of ∼ 10⁴ s) and compact master oscillators/optical clocks with a frequency stability of 10⁻¹⁴–10⁻¹⁵ (for an averaging time of 1 s) based on He–Ne/CH₄ and fiber femtosecond lasers.