Open AccessUltrastable measurement platform: sub-nm drift over hours in 3D at room temperature
Author(s) -
Robert Walder,
D. Hern Paik,
Matthew S. Bull,
Carl O. Sauer,
Thomas T. Perkins
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.016554
Subject(s) - optics , photodiode , microscope , laser , materials science , optical microscope , microscopy , optical instrument , allan variance , optical tweezers , image resolution , optoelectronics , standard deviation , physics , scanning electron microscope , statistics , mathematics
Advanced optical traps can probe single molecules with Ångstrom-scale precision, but drift limits the utility of these instruments. To achieve Å-scale stability, a differential measurement scheme between a pair of laser foci was introduced that substantially exceeds the inherent mechanical stability of various types of microscopes at room temperature. By using lock-in detection to measure both lasers with a single quadrant photodiode, we enhanced the differential stability of this optical reference frame and thereby stabilized an optical-trapping microscope to 0.2 Å laterally over 100 s based on the Allan deviation. In three dimensions, we achieved stabilities of 1 Å over 1,000 s and 1 nm over 15 h. This stability was complemented by high measurement bandwidth (100 kHz). Overall, our compact back-scattered detection enables an ultrastable measurement platform compatible with optical traps, atomic force microscopy, and optical microscopy, including super-resolution techniques.