Optical feedback stabilized laser tuned by single-sideband modulation

Abstract

We report a subkilohertz-linewidth distributed-feedback diode laser that is optical-feedback locked to a highly stable V-shaped cavity with drift rates below 20 Hz/s. This source is continuously tunable over 1 THz around 1590 nm by selecting a cavity mode and using an innovative single-sideband modulation scheme, which allows for frequency shifting over up to 40 GHz with millihertz accuracy. This robust setup achieves high performance without advanced vibration isolation and will be a powerful tool for metrological applications, in particular a redetermination of the Boltzmann constant by molecular spectroscopy.

Communication: Saturated CO2 absorption near 1.6 μm for kilohertz-accuracy transition frequencies

“…Arbitrarily fine tunability for high-resolution molecular spectroscopy is achieved by singlesideband modulation using an integrated dual-parallel Mach-Zehnder modulator (MZM). 16 The length of the massive, rugged ring-down (RD) cavity is tightly locked to this VCOF (V-cavity-based optical feedback) source by means of a Pound-Drever-Hall (PDH) locking scheme using a fiber-optic circulator. This guarantees an unbroken stability transfer chain from the V-shaped reference cavity to the spectral x axis as well as a near-optimal resonant intra-cavity intensity buildup.…”

Recent advances in collisional effects on spectra of molecular gases and their practical consequences

“…This step stabilizes the probe laser frequency and renders its bandwidth narrow by comparison to that of the ring-down cavity mode. Second, continuous optical tuning is realized up to 20 GHz using a single-sideband optical modulator, transforming the stabilized single-frequency light source into an arbitrarily tunable probe laser [52]. Third, the ring-down cavity is locked to the probe laser allowing CRDS spectra to be acquired with fully adjustable resolution and high SNR.…”

All-fiber versatile laser frequency reference at 2 μm for CO2 space-borne lidar applications

“…This is an optimal configuration since a maximum optical power can be transferred into a single sideband, which can be locked to the considered molecular transition without any perturbation induced by the presence of spurious sidebands. The use of an SSB-EOM in a similar configuration has been demonstrated in the near-infrared spectral region of 1.59 μm for the realization of a continuously tunable laser source with a narrow linewidth and precise frequency control by sideband locking to a high-finesse optical cavity [24]. However, such a component is not available in the wavelength range of 2 μm.…”