Axial Calibration of QPD Signal based on Stuck Bead Method for Optical Trapping Applications
Keywords:Axial QPD Signal, Optical Tweezer, Stuck Bead Method
Calibration of axial quadrant photodetector (QPD) signal to the trapped bead position in an optical tweezer is important to measure the quantitative mechanical parameter in axial (laser propagation) direction. An alternative calibration based on the Stuck Bead Method (SBM) was proposed in this study. 3 µm polystyrene beads were stuck at the surface of glass coverslip and moved axially around the laser focus. QPD was used to obtain the position dependent intensity profile at three different laser powers (19.8 mW, 34.1 mW, 48.5 mW). The QPD signal-to-distance calibration value was consistent at 26 mV/µm for the used bead at the three laser powers. It was found that the calibration values are independent of laser powers and limited by the resolution of distance adjustment.
 Bendix P, Jauffred L, Norregaard, K & Oddershede L (2014), Optical trapping of nanoparticles and microparticles. IEEE Journal of Selected Topics in Quantum Electronics, 20(3).
 Deufel C & Wang MD (2006), Detection of forces and
displacements along the axial direction in an optical trap.
Biophysical Journal, 90(2), 657â€“667.
 Hamid MY & Ayop SK (2018), LabVIEW-Based Software for Optical Stiffness Determination Using Boltzmann Statistics,
Equipartition Theorem and Power Spectral Density Methods.
Advanced Science Letters, 24(3), 1856â€“1860.
 Jun Y, Tripathy SK, Narayanareddy BRJ, Mattson-Hoss
MK & Gross SP (2014), Calibration of optical tweezers for in vivo force measurements: How do different approaches compare? Biophysical Journal, 107(6), 1474â€“1484.
 MaragÃ² OM, Gucciardi PG, Bonaccorso F, Calogero G, Scardaci V, Rozhin AG & IatÃ¬ MA (2008). Optical trapping of carbon nanotubes. Physica E: Low-Dimensional Systems and Nanostructures, 40(7), 2347â€“2351.
 Mat Yen, MS, Ayop SK & Hamid MY (2017), The
Determination of Laser Spot Size of an Optical Tweezers by Stuck Bead Method. Journal of Science and Technology, 9(3), 70â€“74.
 Tan S, Lopez HA, Cai CW & Zhang Y (2004), Optical Trapping of Single-Walled Carbon Nanotubes. Nano Letters, vol. 4(8), 1415â€“1419.
 Twombly CW, Evans JS & Smalyukh II (2013), Optical manipulation of self-aligned graphene flakes in liquid crystals.
Optics Express, 21(1), 1324.
 Vermeulen KC, Wuite GJL, Stienen GJM & Schmidt CF (2006), Optical trap stiffness in the presence and absence of spherical aberrations. Applied Optics, 45(8), 1812â€“ 1819.
 Wang SF, Yuyama KI, Sugiyama T & Masuhara H (2016), Reflection Microspectroscopic Study of Laser Trapping Assembling of Polystyrene Nanoparticles at Air/Solution Interface. Journal of Physical Chemistry C, 120(29), 15578â€“15585.
 Yan Z, Jureller JE, Sweet J, Guffey MJ, Pelton M & Scherer NF (2012), Three- dimensional optical trapping and
manipulation of single silver nanowires. Nano Letters, 12(10), 5155â€“5161.
 Yehoshua S, Pollari R & Milstein JN (2015), Axial Optical Traps: A New Direction for Optical Tweezers. Biophysical Journal, 108(12), 2759â€“2766.