Development and realization of a Raman laser system

• Main Author: Chan, Kin Sung
• Other Authors: Rainer Helmut Dumke
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Science::Physics::Optics and light
• Online Access: http://hdl.handle.net/10356/18608
• Institution: Nanyang Technological University

Chapter 1 gives a brief introduction of the physical phenomena that motivates the buiding of Raman laser system. Chapter 2 explains the physics of how laser can be used to cool down an ensemble of atoms. The ensemble of cooled atoms are then trapped by setting up the magneto-optical trap. Chapter 3 will give a mathematical description of two level system under the perturbation of a radiation field. A useful geometrical picture can be derived by writing the dipole moment with new algebraic terms. The Bloch vector derived from there can be used to represent the dynamic nature of the two level system under radiation field on a Bloch sphere. Chapter 3 describes about two level system but there are more interesting properties to be found for three level system. Chapter 4 will use one example of three level system - lambda system and derives a set of mathematical equations called Bloch equation to describe its interaction with radiation field. A phenomenon of quantum interference is observed when the frequency difference between two lasers interacting with an ensemble of atoms are equal to the energy separation of the two ground states. Electromangetically induced transparency (EIT) and coherent population trapping (CPT) are explained and steady state solutions are also plotted. Chapter 5 is the experimental realisation of Raman laser system. It is divided into two sections with chapter 5.1 mentions about the optical setup with the use of two diode laser. The laser beams from the two diode lasers are superposed to create a beat frequency of 6.84 GHz. Chapter 5.2 states about the electronic implementation phase locked loop to the optical setup so that the 6.84 GHz beat frequency is stable and phase locked. Chapter 6 states about the proposals of the Raman laser system into an experimentation.