We are pleased to invite you to a webinair on Self-Mixing Interferometry: a Universal Yardstick to Measure Almost Everything held by Prof. Silvano Donati, Professor Emeritus at the University of Pavia. The event will take place on May 12nd at 11.00 am. In the attachment, the poster of the seminar (which is worth credits, recognized for PhD Students in Electronics, Computer Science and Electrical Engineering).
Thank you and best wishes from the IEEE Student Branch of Pavia and PESB.
Link for the online seminar: https://us02web.zoom.us/j/83389027357?pwd=TFRwaUhaZ3psMGVJWHE3bnk1bmtXZz09
Abstract:
Self-mixing interferometry is a coherent technique for measurement of dimensional and kinematic quantities such as: displacement, distance, vibration amplitude, thickness, angle, and curvature, and of physical quantities like: coupling factors, line width, alfa-factor, and index of refraction. In the measurement arrangement, the laser undergoes self-injection at weak level, leading to AM and FM driven by external optical path length. We report on the development of a displacement-measuring instrument, based on up/down counting of mode hops, and then extend the measurement to the practical case of a diffuse (non-cooperative) target, covering displacements up to 1-m with um-resolution. For sub-um vibrations, we implement a two-channel vibrometer based on analogue processing, removing amplitude errors thanks to a servo-loop. For the first time, we report non-contact measurement of the mechanical frequency response and, even more unusual, hysteresis cycle (or the stress/strain diagram) of a sample under test. Additionally, a number of surprising measurements performed by self-mix will be finally surveyed, i.e., the absolute distance meter, the thickness, angles and return echoes measurements as well as that of laser parameters like linewidth and alpha-factor.
