
Academic Year:  2017/8 
Owning Department/School:  Department of Physics 
Credits:  6 [equivalent to 12 CATS credits] 
Notional Study Hours:  120 
Level:  Honours (FHEQ level 6) 
Period: 

Assessment Summary:  EX 100% 
Assessment Detail: 

Supplementary Assessment: 

Requisites:  Before taking this module you must ( take PH20013 OR take PH20060 ) AND ( take PH20014 OR take PH20061 ) AND ( take PH20020 OR take MA20223 ) 
Description:  Aims: The aims of this unit are to provide the theoretical background for what is required for laser action and then to show how this is achieved in real lasers. Learning Outcomes: After taking this unit the student should be able to: * understand how light interacts with atoms in excited states, and how this can lead to stimulated emission and lasing. * theoretically design simple laser resonators. * analyse continuous and pulsed lasers and discuss how laser pulses are formed. * compare the properties of different materials for use in practical lasers. Skills: Numeracy T/F A, Problem Solving T/F A. Content: Interaction of light with matter (2 hours): Introduction, absorption, spontaneous and stimulated emission; lineshape and broadening mechanisms, gain and population inversion. Conditions for oscillation (2 hours): Gain in 3 and 4 level systems, gain saturation, introduction to laser cavities, lasing threshold, output power in lasers above threshold, gain clamping, laser efficiency. Optical beams and resonators (5 hours): Ray vectors and matrices, spherical waves, Gaussian beams. Rayleigh length, beam waist, phase front curvature. Resonators with parallel or curved mirrors; stability criterion. Optical modes in resonators, cavity Q factor and lifetime. Types of gain medium (6 hours): Examples of specific lasers and pumping mechanisms: gas, dye, solid state, semiconductor and fibre lasers. Pulsed lasers (5 hours): Qswitching. Modelocking; timebandwidth product for pulses. Examples of pulsed lasers. Dispersion; Pulse spreading caused by group velocity dispersion, frequency chirp. Frequency conversion (2 hours): secondharmonic generation, phasematching. 
Programme availability: 
PH30032 is Optional on the following programmes:Department of Mathematical Sciences

Notes:
