Portable optical frequency standard based on sealed gas-filled hollow-core fiber using a novel encapsulation technique

Abstract

A portable stand-alone optical frequency standard based on a gas-filled hollow-core photonic crystal fiber is developed to stabilize a fiber laser to the $$^{13}\hbox {C}_2\hbox {H}_2$$ P(16) ( $$\nu _1 + \nu _3$$ ) transition at 1542 nm using saturated absorption. A novel encapsulation technique is developed to permanently seal the hollow-core fiber with easy light coupling, showing negligible pressure increase over two months. The locked laser shows a fractional frequency instability below $$8 \times 10^{-12}$$ for an averaging time up to $$10^{4}$$ s. The lock-point repeatability over one month is $$2.6 \times 10^{-11}$$ , corresponding to a standard deviation of 5.3 kHz. The system is also assembled in a more compact and easy-to-use configuration (Plug&Play), showing comparable performance with previously published work. The real portability of this technology is proved by shipping the system to a collaborating laboratory, showing unchanged performance after the return.