The development of new pulsed optical sources with high pulse stability allows the improvement of common contactless measurement techniques. A new two-way optical rangefinder, employing a femtosecond laser, is presented here from design to implementation. The system is based on the evaluation of the phase delay of the returning optical pulse train with respect to the outgoing one. The main idea is to expand the time interval corresponding to the phase delay by harmonic heterodyne downconversion of a high harmonic of the pulse repetition rate (up to 10 GHz), which is applied symmetrically to the two channels. The system has shown 10 μm repeatability with a resolution that improves proportionally to the number of the employed harmonic.
High-Resolution Mode-Locked Laser Rangefinder With Harmonic Downconversion / Pesatori, A.; Norgia, M.; Svelto, C.; Zucco, Massimo; Stupka, M.; De, Marchi. - In: IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT. - ISSN 0018-9456. - 99:(2012), pp. 1-9. [10.1109/TIM.2012.2183437]
High-Resolution Mode-Locked Laser Rangefinder With Harmonic Downconversion
ZUCCO, MASSIMO;
2012
Abstract
The development of new pulsed optical sources with high pulse stability allows the improvement of common contactless measurement techniques. A new two-way optical rangefinder, employing a femtosecond laser, is presented here from design to implementation. The system is based on the evaluation of the phase delay of the returning optical pulse train with respect to the outgoing one. The main idea is to expand the time interval corresponding to the phase delay by harmonic heterodyne downconversion of a high harmonic of the pulse repetition rate (up to 10 GHz), which is applied symmetrically to the two channels. The system has shown 10 μm repeatability with a resolution that improves proportionally to the number of the employed harmonic.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
