Optical Principle of a phase modulating FLCoS SLM
The birefringence of the liquid crystal material introduces a phase delay, allowing the FLCoS to be employed as a Spatial Light Modulator (SLM), operating as a high speed binary (0 or π ) phase modulator of coherent light from a laser. Using the QXGA-R11, diffraction into the 1st order can be modulated up to 4.5 kHz by fully reconfigurable high resolution grating patterns.
The diffraction efficiency into the first order at room temperature is wavelength-dependent:
10% at 544 nm and 8% at 455 nm.
It’s doubled if positive and negative first order can be used.
For creating transmission functions ForthDD recommends the starter kit from LightTrans. www.lighttrans.com
The binary phase modulation produces no phase jitter and allows for fast speckle reduction by averaging of the far field image thus enabling:
- Wavefront Correction
- Doughnut Beams
- Beam Steering
- Polarisation Control
Applications include (referenced in the tutorial):
- 3D Super Resolution Microscopy techniques:
- Lattice Light Sheet Microscopy, iLLS, TIRF, SPIM, SMLM, Scanning, RIM
- Programmable Array Microscopy
- Holographic Optic Tweezers
- Optogenetics
- 3D Neural Activity Imaging
More details and references can be found in the short tutorial below.