Atomic Physics & Lasers - PHY00065H

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  • Department: Physics
  • Credit value: 10 credits
  • Credit level: H
  • Academic year of delivery: 2022-23

Module will run

Occurrence Teaching period
A Autumn Term 2022-23

Module aims

Students should develop a basic understanding of the quantum mechanical treatments of atomic and molecular structure and the phenomenological nature of the interaction of light with atoms. A basic awareness of the physics of lasers is subsequently developed.

Module learning outcomes

  • Construct energy level diagrams of the fine structure of hydrogen and hydrogen-like ions.
  • Describe the origin of sub-shells, terms and multiplets for atoms with two or more electrons not in closed sub-shells.
  • Describe molecular energy levels, including vibrational and rotational levels.
  • Derive the relationship between the Einstein coefficients.
  • Determine a general formula for laser gain in a generalised four-level laser.
  • Derive an expression for Doppler broadening of a line profile.
  • Describe mode locking of a laser cavity.
  • Describe the operation of helium-neon and carbon dioxide lasers.
  • Describe how lasers can be used to cool atoms to form, for example, Bose-Einstein condensates.

Module content

Syllabus

The quantum mechanics of atoms is introduced by re-visiting the hydrogen atom. Spin orbit splitting and the Lamb shift are introduced leading to a qualitative treatment of fine structure. Exchange parity and the Pauli exclusion principle are presented leading to a discussion of the structure of atoms with more than one electron. The inter-electron Coulomb and spin orbit interactions are introduced leading to a discussion of LS coupling and jj-coupling when there are two or more electrons not in closed sub-shells. The concept of sub-shells, terms and multiplets is presented. Molecular energy levels are introduced starting with the hydrogen molecule ion H2 + . Vibrational and rotational states are discussed. The interaction of light with atoms and molecules is further explored by re-visiting the Einstein A and B coefficient. This leads to a discussion on lasers and the gain coefficient. The concept of the lineshape function is introduced – Doppler broadening is considered. Laser cavities are briefly discussed leading to the concepts of longitudinal modes and mode locking. Helium-neon and carbon dioxide lasers are discussed. The technique of laser cooling is presented with a brief discussion of Bose-Einstein condensates.

Indicative assessment

Task % of module mark
Essay/coursework 40.0
Essay/coursework 60.0

Special assessment rules

None

Indicative reassessment

Task % of module mark
Essay/coursework 40.0
Essay/coursework 60.0

Module feedback

Our policy on how you receive feedback for formative and summative purposes is contained in our Department Handbook.

Indicative reading

Haken H and Wolf H C: The Physics of Atoms and Quanta (Springer).

Hawkes J and Latimer I: Lasers: Theory and Practice (Prentice-Hall).

Tallents, G J ‘An introduction to the atomic and radiation physics of plasmas’ (Cambridge University Press)