Optomechanical control of microscopic objects at low temperature
The last decade has seen the development of optical techniques for the non-contact manipulation of microscopic objects such as bacterial and individual cells. Optical manipulation, or so-called optical tweezers, have been revolutionised by the use of spatial light modulators (SLM) to split a single laser into multiple beams to trap and move many cells simultaneously. Our design of holographic tweezers gives working distances of 20mm which is allowing us to configure the optical traps within a high-pressure, diamond windowed, anvil cell capable of reproducing inter-stellar pressures in the contained sample. The same basic configuration allows access to other non laboratory conditions, such as the possibility to try and trap micro-spheres at cryogenic temperatures.
An area of growing international interest is the optomechanical control/cooling of micro objects, motivated by a desire to observe quantum effects i.e. entanglement and coherence at the microscopic scale. We aim to explore the optical control/suppression of the residual Brownian motion of micron sized spheres suspended in liquid helium. By combining our recent software acceleration of SLMs, our high-speed video feedback to suppress the Brownian motion of a cryogenically cooled microsphere, we will test how “cold” we can get. We will also investigate whether a network of trapped beads can reveal quantum behaviour within the eigenmodes of the hydrodynamically coupled system.
In an initial five year period we would focus on personnel exchanges between UK-German groups working both on scientific goals and technology transfer of expertise of our spatial light modulator control for beam shaping both with respect to manipulation and measurement of matter and light.