Beyond the phase stability in standard Stark deceleration

Improving the number and number density of cold molecules is a longstanding goal in cold molecule research. Stark deceleration provides an important access to taming polar molecules and makes the collision and high-resolution spectroscopy a reality. However, the full deceleration efficiency of the traditional Stark decelerator has been impeded by its intrinsic loss mechanisms, which significantly limit its applications. In this paper, we introduce an interspersed guiding deceleration strategy that surpasses the periodic phase stability limitations of traditional Stark decelerator. Our approach is theoretically and experimentally validated using the $\mathrm{N}{\mathrm{D}}_{3}$ molecule, achieving significant gains of $3\ensuremath{\sim}8$ for all final velocity ranges. Additionally, our method requires a lower operation number of switching that is beneficial for reducing the consumption of the high-voltage switches and suitable for controlling a large number of deceleration stages. This method is applicable to any traditional crossed-pin Stark decelerator and can stop a wider variety of molecular species with higher densities, including those with a small Stark shift-to-mass ratio. It is anticipated to become an essential tool for producing cold and dense molecular samples, offering promising prospects for cold collision studies and precision measurements.