Low-power microstructured atomic oven for alkaline-earth-like elements

Abstract

Alkaline-earth-like elements are of growing interest for their potential in state-of-the-art quantum sensors, most notably optical clocks. Optical lattice clocks (OLCs) based on ytterbium and strontium have achieved remarkable technological adavancement in recent years, reaching fractional frequency uncertainties in the low 10^-18 range. Although transportable systems have been developed that aim for field deployment and even space applications, they still face challenges in meeting the demanding size, weight and power consumption constraints essential for space operation. A significant fraction of an OLC’s overall power consumption stems from the atom source, typically an effusive oven that requires heating to temperatures up to 400 - 500 °C. Progress towards the reduction of the power consumption has been made with a chip-size atomic oven based on silicon. Here, we present a chip-size monolithic atomic oven based on microstructured fused silica, which leverages the very low thermal conductance of fused silica to even further reduce the required heating power. The oven has been manufactured with LIDE (laser induced deep etching). It has a central reservoir that is held by four mounting springs and is heated directly. A laser-structured electrical circuit, in the shape of a Fermat’s spiral, on the back side of the chip allows for electrical heating, as well as heating by optical absorption of light. We characterized the oven by loading an ytterbium magneto-optical trap (MOT) and measuring the MOT loading rate. The MOT is generated by a monolithic pyramid reflector, which requires only a single incident laser beam. The oven is placed directly at the outside of the reflector, minimizing its distance to the trap center. We demonstrate MOT loading rates above 10^8 atoms/s for heating powers below 250 mW. We further demonstrate that the oven can provide a stable flux of atoms when heated electrically, and that trapping and cooling on the narrow triplet transition is possible in this compact setup. Our oven thus constitutes a promising candidate to serve as an atom source for a future highly compact transportable OLC.