Ultra-stable External Cavity Diode Lasers for Laser Cooling
Open Access
- Author:
- Soldner, Andrew James
- Area of Honors:
- Physics
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Nathan David Gemelke, Thesis Supervisor
Dr. Richard Wallace Robinett, Thesis Honors Advisor - Keywords:
- atomic physics
laser cooling
magneto optical trap
optical molasses
collision microscope
external cavity diode laser - Abstract:
- Being able to manipulate and measure properties of atoms in optical lattices is a technique of growing importance throughout atomic physics. Creating a collision microscope in which we use many atoms in parallel to probe a many-atom system confined in an optical lattice will allow us to study fundamental aspects of quantum statistics and thermodynamics. To achieve these aims, atoms must first be cooled to quantum degeneracy. In order to cool the atoms, we use a series of ultra-stable external cavity diode lasers (ECDLs) of a specific wavelength and frequency to create a magneto optical trap (MOT) inside high vacuum. The cooling and trapping effects of the MOT are induced by a magnetic field gradient and optical pumping. The lasers are detuned slightly below the transition frequency of the atoms so that if an atom is moving towards the incoming laser beam, it absorbs more photons as a result of the Doppler Effect. This laser cooling process is adequate to reach temperatures as low as a few hundred micro-Kelvin. By applying additional laser cooling methods of optical molasses and Raman sideband cooling, and finally using evaporative cooling, we can observe atoms at a few hundred nano-Kelvin. Once an optical lattice is setup, another set of lasers can be used in conjunction with a Potassium-40 atom to move it through the Cesium-133 lattice and observe how they interact. This collision microscope technique will allow us to further explore quantum entanglement and the Quantum Hall Effect.