3-D stimulated emission depletion microscopy with programmable aberration correction.

We present a stimulated emission depletion (STED) microscope that provides 3-D super resolution by simultaneous depletion using beams with both a helical phase profile for enhanced lateral resolution and an annular phase profile to enhance axial resolution. The 3-D depletion point spread function is realised using a single spatial light modulator that can also be programmed to compensate for aberrations in the microscope and the sample. We apply it to demonstrate the first 3-D super-resolved imaging of an immunological synapse between a Natural Killer cell and its target cell.

Double pass, common path method for arbitrary polarization control using a ferroelectric liquid crystal spatial light modulator.

We present a method for arbitrary control of the polarization of a light beam. Our method uses two holograms on a binary ferroelectric liquid crystal spatial light modulator (FLCSLM), and so has the potential to allow polarization state switching at kilohertz rates. Unlike previous methods that achieve polarization control using FLCSLMs, our method is common path and requires only the simplest optical components.