Microwave Lens for Polar Molecules

TL;DR

This paper demonstrates a microwave lens capable of focusing polar molecules in various quantum states, advancing the development of microwave-based molecular control devices.

Contribution

It introduces a novel microwave lens design using TE_11m modes for focusing polar molecules in different quantum states.

Findings

The microwave lens effectively focuses Stark-decelerated ammonia molecules.

Focusing properties depend on molecule velocity, microwave detuning, and power.

The device is a step towards microwave decelerators and traps.

Abstract

We here report on the implementation of a microwave lens for neutral polar molecules suitable to focus molecules both in low-field-seeking and in high-field-seeking states. By using the TE_11m modes of a 12 cm long cylindrically symmetric microwave resonator, Stark-decelerated ammonia molecules are transversally confined. We investigate the focusing properties of this microwave lens as a function of the molecules' velocity, the detuning of the microwave frequency from the molecular resonance frequency, and the microwave power. Such a microwave lens can be seen as a first important step towards further microwave devices, such as decelerators and traps.