Lasers and Photonics

PHYS30611 Lasers and Photonics 10 Semester 1 Undergraduate Level 3 Mark Dickinson Unit coordinator Department of Physics & Astronomy 1 FHEQ level (Framework for Higher Education Qualifications) ' Last part of a Bachelors ' European Credit Transfer & Accumulation System Rating : 5.0 Lasers are now commonplace in the world we live in – being used for many applications ranging from games machines and printers to ultra-high-resolution spectroscopy.  It is estimated that there are now more lasers in circulation than there are people on the planet.  Lasers are one of the devices used to produce photonic systems, where light is used for measurement/sensing, communications, data transfer/storage and displays. They are also key to the rapid development of quantum technologies.   This unit provides a grounding in the theory behind the operation of lasers, during which the propagation of Gaussian beams, optical resonators, the interaction of radiation with atomic systems and transient effects are covered.  It also looks at the properties of the light produced, including coherence and the statistical nature of light. On a practical level, specific lasers are discussed, along with methods of detection and modulation.  A number of photonic applications (not necessarily involving lasers), such as communications and displays will also be covered.   Lasers are now commonplace in the world we live in – being used for many applications ranging from games machines and printers to ultra-high-resolution spectroscopy.  It is estimated that there are now more lasers in circulation than there are people on the planet.  Lasers are one of the devices used to produce photonic systems, where light is used for measurement/sensing, communications, data transfer/storage and displays. They are also key to the rapid development of quantum technologies.   This unit provides a grounding in the theory behind the operation of lasers, during which the propagation of Gaussian beams, optical resonators, the interaction of radiation with atomic systems and transient effects are covered.  It also looks at the properties of the light produced, including coherence and the statistical nature of light. On a practical level, specific lasers are discussed, along with methods of detection and modulation.  A number of photonic applications (not necessarily involving lasers), such as communications and displays will also be covered.   The unit aims to provide a grounding in understanding the operation of lasers and providing an introduction into the wider area of photonics.    ILO 1Know the properties and propagation of rays and Gaussian beams through lenses, between mirrors and through optical waveguides, linking this to optical resonators.ILO 2Know the interactions of light with atomic systems, including spontaneous and stimulated emission, and develop an understanding of gain and its saturation, the oscillation conditions, mode structure and transient effects key to Q-switching.  ILO 3Know the properties of laser radiation, including broadening mechanisms, coherence and the statistical nature of light.ILO 4Know details of specific laser systems, detection methods and modulation techniques and then understand a selection of photonic systems used, for example, in communications and for displays.    <ol><li class="pf0">Intro and mathematical formalism  Representation of an EM wave and complex notation  </li><li class="pf0">Propagation of rays and beams  Lens waveguide Rays between mirrors Wave equation and Gaussian beams ABCD law Higher order Gaussian beams  </li><li class="pf0">Propagation of beams in fibres  Waves in cylindrical coordinates Step-index waveguide Graded index fibres Attenuation in silica fibres  </li><li class="pf0">Optical resonators  Fabry-Perot etalon Resonators with spherical mirrors Stability criteria Resonance frequencies Losses in resonators  </li><li class="pf0">Interaction of radiation and atomic systems  Spontaneous transitions and broadening mechanisms Induced transitions Absorption and amplification Electron oscillator model and susceptibility Gain saturation  </li><li class="pf0">Laser oscillation  Fabry-Perot laser Oscillation frequency 3 and 4-level lasers Power and optimum output coupling Multi-mode operation Transient effects – relaxation oscillations Q-switching and mode locking  </li><li class="pf0">Statistic optics and coherence  Random light Interference of partially coherent light  </li><li class="pf0">Specific laser systems Nd:YAG Fibre lasers Semiconductor laser DPSS lasers  </li><li class="pf0">Detection of optical radiation  Photomultiplier Photodiode Noise in detectors  </li><li class="pf0">Modulation  Electro-optics (including liquid crystals) Acousto-optic  </li><li class="pf0">Applications  Fibre-optic communications Displays</li></ol> Two one hour, live in-person lectures per week where the core material with examples will be delivered.  The recordings of these lectures will be on the course online page.  The lectures are accompanied by detailed notes and for some of the material explanatory videos that the students are expected to assimilate before the lecture.  This is augmented weekly by problems.   1 Written exam 100% Feedback & exercises will be available through examples presented during the lectures together with answers available via Blackboard, and through working through the solution of selected examples in the lectures. PHYS20342 Electromagnetism 2 Pre-Requisite Compulsory N Lasers and Electro-optics: C. C. DavisLasers: P. W. Milloni, J. H. Eberly.Introduction to Optical Electronics: A. YarivFundamentals of Photonics: B. E. A. Saleh, M. C. TeichOptoelectronics: An Introduction: J. Wilson, J. F. B. Hawkes  Assessment written exam 1.5 Lectures 22 0 76.5