Long-term stabilization of the length of an optical reference cavity

We propose a modulation-free optical frequency stabilization technique using an interferometric effect between transmitted and reflected lights from a reference cavity. The property of the reflected light brings robustness of the error signal against laser intensity fluctuations as in previous stabilization methods. Due to the property of the transmitted light, the capture range for a specific locking frequency is expanded up to twice the FSR of the cavity, which we experimen...

We describe an apparatus for the implementation of hybrid optomechanical systems at 4 K. The platform is based on a high-finesse, micrometer-scale fiber Fabry-Perot cavity, which can be widely tuned using piezoelectric positioners. A mechanical resonator can be positioned within the cavity in the object-in-the-middle configuration by a second set of positioners. A high level of stability is achieved without sacrificing either performance or tunability, through the combination...

We report on a design of a compact laser system composed of an extended cavity diode laser with high passive stability and a pre-filter Fabri-Perot cavity. The laser is frequency stabilized relative to the cavity using a serrodyne technique with a correction bandwidth of $\geq 6$ MHz and a dynamic range of $\geq 700$ MHz. The free running laser system has a power spectral density (PSD) $\leq 100$ Hz$^{2}$/Hz centered mainly in the acoustic frequency range. A highly tunable, $...

We present the analysis of an unorthodox technique for locking a laser to a resonant optical cavity. Error signals are derived from the interference between the fundamental cavity mode and higher-order spatial modes of order two excited by mode mismatch. This scheme is simple, inexpensive and, in contrast to similar techniques, first-order-insensitive to beam jitter. After mitigating sources of technical noise, performance is fundamentally limited by quantum shot-noise.

We stabilized the frequencies of two independent Nd:YAG lasers to two adjacent longitudinal modes of a high-finesse Fabry-P\'erot resonator and obtained a beat frequency instability of 6.3 mHz at an integration time of 40 s. Referred to a single laser, this is $1.6\times10^{-17}$ relative to the laser frequency, and $1.3\times10^{-6}$ relative to the full width at half maximum of the cavity resonance. The amplitude spectrum of the beat signal had a FWHM of 7.8 mHz. This stabl...

We report the relative frequency stabilization of a distributed feedback erbium-doped fiber laser on an optical cavity by serrodyne frequency shifting. A correction bandwidth of 2.3 MHz and a dynamic range of 220 MHz are achieved, which leads to a strong robustness against large disturbances up to high frequencies. We demonstrate that serrodyne frequency shifting reaches a higher correction bandwidth and lower relative frequency noise level compared to a standard acousto-opti...

We present a novel locking scheme for active length-stabilization and frequency detuning of a cavity optomechanical device based on the optical spring effect. The scheme can be used as an alternative to the Pound-Drever-Hall locking technique but in contrast doesn't require signal processing on time-scales of the cavity decay rate. It is therefore particularly suited for stabilizing micro cavities, where this time-scale can be extremely fast. The error signal is generated thr...

Thermal noise in optical cavities imposes a severe limitation in the stability of the most advanced frequency standards at a level of a few 10^(-16) (s/t)^(1/2) for long averaging times t. In this paper we describe two schemes for reducing the effect of thermal noise in a reference cavity. In the first approach, we investigate the potential and limitations of operating the cavity close to instability, where the beam diameter on the mirrors becomes large. Our analysis shows th...

We present a stabilization technique developed to lock and dynamically tune the resonant frequency of a moderate finesse Fabry-P\'erot (FP) cavity used in precision atom-cavity quantum electrodynamics (QED) experiments. Most experimental setups with active stabilization either operate at one fixed resonant frequency or use transfer cavities to achieve the ability to tune the resonant frequency of the cavity. In this work, we present a simple and cost-effective solution to act...

We give a simple introduction to the properties and use of ultrastable optical cavities, which are increasingly common in atomic and molecular physics laboratories for stabilizing the frequency of lasers to linewidths at the kHz level or below. Although the physics of Fabry-Perot interferometers is part of standard optics curricula, the specificities of ultrastable optical cavities, such as their high finesse, fixed length, and the need to operate under vacuum, can make their...