An electrostatic mirror for neutral polar molecules

An electrostatic mirror for neutral polar molecules has been constructed using an array of electrodes of alternating polarity between which a high potential was applied. This configuration produces an exponentially evanescing electric field that interacts with polar molecules by the Stark effect. The spatial gradients of the Stark energies produce forces which were used to reflect a pulsed beam of chloromethane (CH₃Cl) molecules with a reflectivity of 25% at grazing angles of incidence of around 5 mrad. Reflections have also been produced with applied voltages as low as 100 V or with grazing angles greater than 20 mrad. This type of device could be useful for the manipulation of slow molecular beams and would permit the construction of optical elements for the de Broglie waves of molecules.