Towards non-blind optical tweezing by finding 3D refractive index changes through off-focus interferometric tracking.
Benjamin Landenberger1,2, Yatish1,3,4, Alexander Rohrbach5,6,7
1Laboratory for Bio- and Nano-Photonics, Department of Microsystems Engineering-IMTEK, University of Freiburg, 79110, Freiburg, Germany.
Nature Communications
|November 27, 2021
Summary
Researchers developed a new method for precise 3D microscopy. This technique uses holographic optical traps to track and orient biological specimens, improving control in 3D light microscopy.
Area of Science:
- Biophysics
- Optical Microscopy
- Biotechnology
Background:
- Current 3D microscopy struggles with precise manipulation of biological specimens using optical forces.
- Existing optical trapping methods often lack the precision for orienting large or complex samples, leading to slippage.
Purpose of the Study:
- To develop a non-blind optical trapping approach for precise localization and tracking of biological specimens.
- To enable computer-controlled orientation and feature-optimized laser scanning for 3D light microscopy.
Main Methods:
- Utilizing multiple holographic optical traps controlled by a single camera in an off-focus position.
- Analyzing beam deformations from defocused camera images of cellular structures to estimate 3D grabbing positions.
- Parallel tracking of regions with increased refractive index around trapping foci.
Main Results:
- Successfully localized and tracked regions with increased refractive index in parallel using holographic optical traps.
- Enabled estimation of 3D grabbing positions by analyzing beam deformations in real-time.
- Demonstrated an advancement towards non-blind optical trapping for biological samples.
Conclusions:
- This method represents a significant step towards fully computer-controlled orientation of sub-millimeter biological specimens in 3D light microscopy.
- The approach facilitates feature-optimized laser scanning, enhancing future 3D imaging capabilities.
