David Engström

Institution/Department: Department of Physics
Previous studies: Chalmers University of Technology; University
of Cambridge, UK; University of Colorado at Boulder, USA.
Thesis: Multi-Level Lossless Phase Modulation in Liquid Crystals for High-Speed Spatial Light Modulators
Research areas: Optical tweezers, Spatial light modulators, Phase modulation based on Liquid crystals, Diffractive optics, Beem steering, and Optical chirality detection
Current research: Optical tweezers (OTs) utilize a highly convergent laser focus to trap a particle, e.g., a glass bead or a living cell.
The OTs were invented in the mid 80’s but not until recently has the spatial light modulator (SLM) been implemented in the setup in order to allow for multiple, individually steerable, traps. The SLM allows for parallel investigation of cells, advanced movement of objects with a length scale on the order of 1 micrometer, force measurements, etc. However, far from the full potential of the SLM has been utilized yet. The aim for my research is to contribute in the development of the SLM-based OTs. A recently finished project focused on how accurately the position of an optical trap can be controlled using an SLM. Currently, work is focused on creating an algorithm for precise 3D positioning of multiple optical traps. Such an algorithm will allow for, e.g., obtaining a sharp image of the cell core of multiple cells in a single measurement. In the long run, the goal is to be able to measure forces between two, or more, objects (such as cells) using an SLM-based OTs.

E-mail address: david.engstrom@physics.gu.se