Ultranarrow Linewidth Photonic-Atomic Laser

摘要

Lasers with high spectral purity can enable a diverse application space,including precision spectroscopy, coherent high-speed communications,physical sensing, and manipulation of quantum systems. Already, meticulousdesign and construction of bench Fabry–Perot cavities has made possibledramatic achievements in active laser-linewidth reduction, predominantly foroptical-atomic clocks. Yet, there is increasing demand for miniaturized lasersystems operating with high performance in ambient environments. Here,a compact and robust photonic-atomic laser comprising a 2.5 centimeterlong, 20 000 finesse, monolithic Fabry–Perot cavity integrated with amicromachined rubidium vapor cell is presented. By leveraging the short-timefrequency stability of the cavity and the long-time frequency stabilityof atoms, an ultranarrow-linewidth laser that enables integration for extendedmeasurements is realized. Specifically, the laser supports a fractional-frequencystability of 1 × 10~(−13) at an averaging time of 20 millisecond, 7 × 10~(−13)at 300 second, an integrated linewidth of 25 Hz that results from thermalnoise, frequency noise floor as low as 0.06 Hz~2 Hz~(−1), and a passive vibrationimmunity as low as 10~(−10) g~(−1). The present work explores hybrid laser systemswith monolithic photonic and atomic packages based on physical design.