25 October 2004 Vertical-scanning profilometry having nanometric height resolution and scanning speed more than 40 μms/s
Author Affiliations +
Proceedings Volume 5602, Optomechatronic Sensors, Actuators, and Control; (2004) https://doi.org/10.1117/12.570550
Event: Optics East, 2004, Philadelphia, Pennsylvania, United States
I propose a high-speed vertical scanning profilometry which has nanometric height resolution. The proposed profilometry is equipped with two short-coherent-light sources, which are made of extremely-high-power light emitting diodes ( LED) and whose center wavelengths are 503 and 591 nm. In 3-D profile measurements, this profilometry acquires many interferograms while vertically-scanning a Mirau-type microscope objective with 0.415-mm step/interferogram and alternately-flashing LED. Odd-numbered interferograms are acquired with 503-nm LED and even-numbered interferograms are with 591-nm LED. Regarding the acquired interferograms, a computer calculates phase and modulation contrast using a phase-shifting technique. As two step movements are repeated between acquirements of interferograms flashed with the same LED, phase step corresponds to approximately 6 p + p/2 with 503 nm and approximately 6 p - p/2 with 591 nm, respectively. After searching the interferogram having a contrast peak, the computer extracts optical path difference of the searched interferogram with nanometric resolution from the phase information. From the vertical step length of 0.415 mm and a frame rate of 110 Hz, a vertical scanning speed is given as 46 mm/s. Height resolution of the profilometry is confirmed from measured data of a step height standard.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Masaaki Adachi, Masaaki Adachi, } "Vertical-scanning profilometry having nanometric height resolution and scanning speed more than 40 μms/s", Proc. SPIE 5602, Optomechatronic Sensors, Actuators, and Control, (25 October 2004); doi: 10.1117/12.570550; https://doi.org/10.1117/12.570550

Back to Top