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In atomic, molecular, and optical physics, a magneto-optical trap (MOT) is an apparatus which uses laser cooling and a spatially-varying magnetic field to create a trap which can produce samples of cold, neutral atoms.

A MOT is formed from the intersection of a weak, quadrupolar, spatially-varying magnetic field and six circularly-polarized, red-detuned, optical molasses beams. As atoms travel away from the field zero at the centre of the trap (halfway between the coils), the spatially varying Zeeman shift brings an atomic transition into resonance which gives rise to a scattering force that pushes the atoms back towards the centre of the trap. This is why a MOT traps atoms, and because this force arises from photon scattering in which atoms receive momentum “kicks” in the direction opposite their motion, it also slows the atoms (i.e. cools them), on average, over repeated absorption and spontaneous emission cycles. In this way, a MOT is able to trap and cool atoms with initial velocities of hundreds of meters per second down to tens of centimetres per second (again, depending upon the atomic species).

Our new range of atom trap chambers are manufactured from 316LN stainless steel with 316LN flanges, and contain up to 14 horizontal and two vertical ports, six of which are used to house three pairs of counter-propagating laser beams that perform the trapping. High quality fused silica optics that offer a high threshold to laser damage (complete with non-magnetic weld rings) are welded directly to the chamber body to reduce the overall chamber size, with an option for custom anti-reflective coatings that are optimised to the wavelengths of the lasers being used.

All of our atom trap chambers are custom-made based on the requirements of the customer.

The custom atom trap chamber pictured was manufactured from 316LN. The λ/4 Fused Silica optics were coated on both faces with our broadband coating, fine-tuned for the best performance between 852nm and 935nm. The big optics offer 85mm clear view. To avoid thermal distortion, we indium sealed the optics. Maximum bake-out temperature for the chamber is 120°C.

This is one of four chambers ordered by our customer.

If you have any questions or if you would like to make an enquiry, you can contact our sales team at sales@torrscientific.co.uk.