Electronics Engineering

EUGENIO FAZIO

The course has as its objective to acquire detailed knowledge on light, his behavior and the major optical components and devices adapted to its processing.
The lessons are then directed to deepen the knowledge of the propagation of light as waves, analyzing the phenomena of interference and diffraction.
They will be analyzed, in geometrical optics regime, the main optical and active components as well as the guided optical properties. Will data elements for the advanced optical design.

Students attending the Optics course will learn the physics of light and the dependence of light phenomena on the wave nature of the electromagnetic field.
Students should be able to:
Have a thorough understanding of the fundamental principles of geometric and physical optics. Know the laws governing the propagation, interference, diffraction, and polarization of light. Be familiar with optical materials, including nonlinear crystals and optical fibers.
Understand the operating principles of the main optical instruments and systems, both classical and modern (microscopes, spectrometers, interferometers).

Students must know the physics of electricity and magnetism as it is done in the courses of Physics 2. The course is delivered in English so they must know the English language well.

Electromagnetic waves and light
Maxwell equations and EM wave equation. Spherical and plane waves. Frequencies and wavelengths of EM waves. Microscopical interpretation of the refractive index. Active and reactive polarisation and the complex refractive index. Sellmeyer equation for the refractive index dispersion. Abbe number and Abbe space for glasses. Poynting vector and light energy. Lightning quantities.
Reflection and refraction
Fermat “minimal action” principle and Snell’s Laws. Fresnel coefficients. Critical angle and total reflection regime. Evanescent waves and Goos-Hänchen phase shift. Geometrical interpretation of optical fibres and waveguides.
Geometrical Optics
Short wavelength approximation. Reflection and mirrors. Refraction and dioptric surfaces. Thin lenses. Thick lenses and principal planes. Centred optical systems. Pupils/stops/f-number/numerical aperture. Vignetting and cosine-to-the-fourth-power law. Principal optical aberrations. Chromatic aberration and achromatic doublet. Fundamental refractive systems. Ray-tracing and ABCD matrices.
Interference and interferometers
Interference of 2 co-propagating waves. Wave beating. Continuous waves and pulses. Phase and group velocities. Spatial and temporal interference. Young’s experiment. Interference of 2 contra-propagating waves: stationary waves and resonators. Fabry-Perot resonator. Optical fibres as transverse resonators. Multilayer interferent systems. Design of dielectric mirrors and band-pass filters. Michelson and MachZehnder interferometers.
Diffraction
Huygens-Fresnel principle and integral. Near field regime and Fresnel Integral. Far field and Fraunhofer integral. Diffraction from a slit. Focusing limit of a lens. Diffraction from a stop. Diffraction from a grating. Harmonic and anharmonic gratings. Nano-optics.
Anisotropic optics
Anisotropic crystals. Index Ellipsoid. Uniaxial and biaxial crystals. Dichroism. Retardation plates.
Nonlinear Optics
Nonlinear response. Anharmonic oscillator. Second order effects. The nonlinear optical tensor. Optical harmonic generation. Parametric effects. The Pockels electro-optic effect. Electro-optic modulators. Photorefractivity and self-assembling optical structures. Spatial solitons and solitonic waveguiding. Smart systems, Machine Learning and Photonic Artificial Intelligence.

M. Born & E. Wolf, Principles of Optics, Pergamon Press
F. Gori, Elementi di Ottica, Accademia
K.D. Moller, Optics, Springer
G. Chartier, Introduction to Optics, Springer

The course is held both face to face and remotely.
General information on the course is published on the website of the Department of Basic and Applied Sciences for Engineering (SBAI) on the teacher's page.
From year to year, the teacher will also activate a GOOGLE CLASSROOM page of the course to which students must register with the Sapienza institutional email address. All communications between teacher and students will be published on the course page, as well as the links for distance learning as well as the didactic material that will be produced during the lessons (copy of what is written or projected during the lessons and any video recordings of the lessons).
On the first day of class, all participants will be given and explained the course that will be followed.

Attendance is not compulsory although it is highly recommended in order to fully understand the program topics. During the lessons a special effort is made to explain all the mathematical passages necessary for the development of the topic.

The student's ability to reason on electromagnetic waves will be evaluated, to have understood the main phenomena of light and to be able to discriminate between them in a real case presented. The evaluation test consists of an oral interview.

diffraction of light; the Huygens-Fresnel principle; thin lenses; anisotropic materials