This hologram can be written such that each individual output beam can have individually specified characteristics arranged in arbitrary three-dimensional configurations. By changing the hologram, which is updated by the SLM in real-time, the output beams can be moved in lateral and axial dimensions arbitrarily. Because this technique is non-mechanical, holographic beam steering enables fully independent and random access addressing of each output beam.
Shown below is an example of this multi-spot beam steering. The left picture is a phase pattern that generates 1681 individually focused spots. The BNS SLM displayed this hologram in phase, and the output light is shown in the two (2) photographs to the right of the hologram. The middle image is the output pattern with the 0th order spot in the same plane as the 1681 spots, and the image on the right has the 0th order shifted away from the plane of the spots.
Using this technique, each focused spot can be as small as the diffraction-limited laser spot because an SLM can simultaneously correct for aberrations while producing a 3D volume of focal points. BNS devices are typically used to generate hundreds of diffraction limited spots from a single beam for applications such as photostimulation and holographic optical trapping (HOT).
BNS is currently working to push the boundaries of this technique even further through the development of new SLM backplanes, high-speed addressing schemes, and low latency 16-bit PCIe drivers to achieve 1 ms closed-loop modulation speeds and beyond. In addition, BNS is developing large format backplanes with higher pixel counts to expand the addressable field of regard.