Comparison of loading double-loop microtraps from a surface MOT and a FORT

• Published in: Applied physics. B, Lasers and optics Vol. 115; no. 1; pp. 61 - 67
• Main Authors: Jian, B., van Wijngaarden, W. A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2014
• Subjects: Adjustment; Clouds; Dipoles; Engineering; Forts; Ground state; Lasers; Linear arrays; Magnetic fields; Optical Devices; Optics; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Quantum Optics; Atom Cloud; Trap Atom; Bias Field; 87Rb Atom; Trap Depth
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-013-5573-4

Two methods to load a microtrap consisting of two concentric microwire loops of radii 300 and 660 μm carrying oppositely oriented currents are demonstrated. Atoms can be directly loaded into the microtrap from a surface magneto-optical trap or alternatively using a far-off resonance optical dipole trap (FORT) as an intermediate step. About 1 × 10 5 87 Rb atoms can be loaded into the microtrap using either technique although the FORT achieves a lower temperature. The FORT is well suited to loading a linear array of 3 microtraps that are aligned with the propagation direction of the infrared laser. Atoms can be trapped in either the 5 S 1 / 2 F = 1 or 2 ground state hyperfine level. The position of the microtrapped atom cloud can be precisely adjusted using a bias magnetic field over a distance of 350 to slightly <50 μm from the atom chip surface.