Cryogenic monocrystalline optical cavity for laser stabilization and precise time measurements

摘要

The feasibility of stabilizing the frequency of a laser by locking it to a resonance of a cryogenic Fabry-Perot optical cavity was tested. The resonant frequencies of a Fabry-Perot cavity are precisely determined by its dimensions, and the use of low-expansivity materials offers the prospect of arbitrarily low drift rates in the cavity dimensions at low enough temperatures. Advances in materials processing motivated by the semiconductor industry have provided a supply of high-purity, low-expansivity materials available in monocrystalline form. Silicon appears to have a thermal expansion coefficient lower than most other materials below 5 K. Thus, a 1.6 kg single crystal of silicon was obtained from which a reference cavity was made.