Laser physics, non-linear and quantum optics [SPHYM109]

Learning outcomes

On the one hand : The first objective is to provide a basic knowledge of laser physics. The different components of a laser will be explained in detail as well as the properties of laser radiation. The second objective is to understand the operation of some lasers such as the He-Ne laser, the CO2 laser, the diode laser and the OPO-based laser. For each, the constituent elements and their characteristics will be detailed. The main applications will also be given. On the other hand : To master the essential physical concepts associated with two fundamental aspects of optics, which are now essential both scientifically and technologically: nonlinear optics and quantum optics. To know the main nonlinear optical phenomena and their applications. To understand the role of the quantum nature of light in contemporary optics and to deepen one's understanding of the foundations of quantum mechanics.

Content

On the one hand, this course is a presentation of the physics of lasers. The concepts of laser are first presented: active medium (stimulated emission, Einstein's equations ...), pumping (electrical, optical ...), resonant cavity (laser oscillator ...). As the lecture progresses, the basic physics concepts are recalled (absorption, emission, etc.). Then, the properties of laser radiation are explained. Equipped with these concepts, several types of laser are described in detail (operation, properties and applications). Theoretical courses are combined with tutorials. On the other hand, the course addresses two major aspects of modern optics: nonlinear optics (NL) and quantum optics. From phenomenological models, we will describe the NL response of materials to electromagnetic (e.m.) excitation and adapt Maxwell's equations to account for it. We will study the propagation of e.m. waves in NL media and at their surfaces (reflection, refraction). We will analyse a series of stationary and dynamic NL phenomena. We will quantify the NL response of materials and see the usefulness of NL optical spectroscopies. We will quantify the e.m. field and characterise it (Fock, coherent, compressed states). We will describe photon correlations and photon pair production by parametric fluorescence. We will study the quantum behaviour of interferometers (Mach-Zehnder, Franson, Hong-OuMandel). We will see how quantum optics experiments allow us to deepen our understanding of the foundations of quantum mechanics (violation of Bell's inequalities, notions of locality, superposition and entanglement) and offer innovative applications (teleportation, quantum cryptography, metrology).