https://www.selleckchem.com/pr....oducts/quinine-dihyd
A system providing an optical frequency with instability comparable to that of a hydrogen maser is presented. It consists of a 5 cm long, vertically oriented silicon optical resonator operated at temperatures between 1.5 K and 3.6 K in a closed-cycle cryostat with a low-temperature Joule-Thomson stage. We show that with a standard cryostat, a simple cryogenic optomechanical setup, and no active or passive vibration isolation, a minimum frequency instability of 2.5 × 10-15 at τ = 1500 s integration time can be reached. Th