Slow atoms

• Main Author: Ew, Chee Howe
• Other Authors: Rainer Helmut Dumke
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Science
• Online Access: http://hdl.handle.net/10356/60785
• Institution: Nanyang Technological University

In this final year project, we constructed a Zeeman Slower as well as the optical setup required for beam deceleration. A single layered variable pitch coil was used to achieve the required magnetic field profile in the Zeeman Slower, such that the atoms are kept in resonance with the Zeeman Slower laser. This allows the atoms to be decelerated as they experience a radiation pressure force when they interact with the Zeeman Slower laser. Water cooling in the coils was implemented to prevent the coils from overheating due to high operating currents. For the optical setup, two Interference Filter External Cavity Diode Laser (IF-ECDL) were built for the repumper laser and the Zeeman Slower laser. The optical power of the Zeeman Slower laser was amplified using a tapered amplifier in a Master Oscillator Power Amplifier (MOPA) configuration. This is to achieve saturation intensity, so that the atoms are slowed sufficiently to be captured in a Magneto-Optical Trap. The frequencies of both lasers were stabilized within 1MHz to the required optical transition of Rb87 via two different techniques; AC Locking was used for the repumper laser and a Frequency Offset Lock for the Zeeman Slower laser. The desired frequencies of various beams (repumping beam, imaging beam and the pumping beam) were then achieved through the use of Acousto-Optic Modulators (AOMs). In this report, we described the realization of the Zeeman Slower, as well as the assembly of different optical and electronics elements for the optical system.