A spatial light modulator (SLM) is an electrically programmable device that modulates light according to a fixed spatial (pixel) pattern. SLMs have an expanding role in several optical areas where light control on a pixel-by-pixel basis is critical for optimum system performance.

All of our 512×512 format SLMs operate with a unique high speed backplane which refreshes each pixel at a rate of 6kHz. This is critical in maintaining high temporal stability, represented as phase ripple across the SLM and stability in the reflected image.

When enabling ODP on Meadowlark’s SLMs, the phase transition time between consecutive holograms is greatly reduced. The use of ODP has shown reductions of 2 – 8x from the standard optical response times. This response time reduction comes from the combination of three separate technology developments integrated together into a single product: Transient Nematic Effects, Phase Wrapping and Regional Look‐up‐tables.

Transient Nematic Effects
The base technology is the transient nematic effect, utilizing intermediate transition voltages beyond the target voltage needed to achieve the desired phase value. This “OverDrive” bypasses the traditional exponential rates of nematic liquid crystals.

 

Download the datasheet

 

Unique Features:

  • Significantly faster response times via transient nematic effect, phase wrapping, and regional calibrations.
  • Ability to enable/disable ODP via software.
  • Utilizes GPU via OpenCL to reduce the time to calculate intermediate holograms.
  • Ability to pre‐calculate intermediate holograms for faster frame rates.
  • Regional calibration routines for 512 x 512 pixel SLMs enabling pixel‐level LUTS and calibration data./li>
OverDrive Plus Spatial Light Modulator
Design wavelengthλ = 1064 nm
Array size7.68 x 7.68 mm
Zero-order diffraction
Efficiency (standard)
61.5% (maximum)
External windowBBAR coated for Ravg < 1.25%
Fill factor0.834
Format512 x 512 (262,144 active pixels)
Phase stroke (double pass)
Pixel pitch15 x 15 μm
Phase rippleAs low as 0.1%, based on SLM configuration
Reflected wavefront distortion (calibrated)λ/10 @ 1064 nm
Liquid crystal response time, 10‐90% (standard)≤ 66.7 ms
Liquid crystal response time, 10‐90% (high-speed)≤ 10 ms
Liquid crystal response time, 10‐90% (OverDrive Plus)≤ 1 ‐ 4 ms