Spatial Light Modulator (SLM) Technology
Fast, flexible shaping of optical phase and amplitude using high-performance liquid crystal on silicon (LCoS) spatial light modulator (SLM) technology
We offer phase-modulating SLMs with industry-leading frame rates and phase accuracy.
Using custom liquid crystals, high-voltage backplanes, novel pixel addressing schemes, and low latency PCIe drivers, BNS provides the fastest LCoS phase-modulating SLMs in the industry. In addition to our standard 1536x1536 and 768x768 pixel arrays, we can develop custom LCoS SLM devices and systems with a range of leading capabilities:
- Phase-only, amplitude-only, or combined phase and amplitude modulation in a single SLM
- Unique modulators, such as polarization-independent SLMs
- Fast switching speeds: > 600 Hz for full analog phase modulating SLMs
- Mirrored backplanes providing 100% effective fill factor for reduced diffractive losses
- Sub-millisecond addressing to suppress phase ripple for higher efficiency
- Low-latency 8-bit and 16-bit PCIe drivers for fast and accurate control
- Large format backplanes up to 30 mm x 30 mm with millions of pixels
SLMs, beam steering, entire optical systems — if what you need doesn't exist yet, we can make it happen.
Dr. Janelle Shane
Senior Research Scientist
We are pushing SLM technology to its limits.
Since 1988, BNS has been advancing the state-of-the-art in liquid crystal on silicon (LCoS) spatial light modulator (SLM) technology. These LCoS SLMs use an array of independent liquid crystal pixels to shape an incident wavefront. As such, these devices can modulate a beam of light to add information to it, often in ways that shape, correct, and/or steer it.
At BNS, we have been at the forefront of new LCoS SLM development, with a range of industry firsts for speed, size, and functionality that stretch back decades. Whether you need a high-speed 1536x1536 or 768x768 array, a custom SLM, or a SLM-based optical system, we want to provide your SLM solution.
|Resolution||1536 x 1536||768 x 768|
|Pixel Pitch||20 μm x 20μm||20 μm x 20μm|
|Array Size||30.7 mm × 30.7 mm||15.4 mm × 15.4 mm|
|True Zero-Order Diffraction Efficiency*||78.5%||78.5%|
|Controller Phase Levels||65,536 / 16 bits||65,536 / 16 bits|
|SLM Phase Levels (Resolvable)||≥ 256 linear levels (8-bit), 2π phase stroke||≥ 256 linear levels (8-bit), 2π phase stroke|
|Maximum Efficient Frame Rate**||500 Hz||600 Hz|
|On-Board Image Storage***||2,045||8,180|
|Trigger Response for On-Board Images||6 μs latency / 3-9 μs jitter||
6 μs latency / 3-9 μs jitter
*Zero-order diffraction efficiency based on experimentally measured data on fully built SLM head at 1064 nm. As an experimentally measured value, small unit-to-unit variations are possible. Take care when comparing against calculated theoretical maximum values, values for only the backplane without other losses included, or reports of peak values for other wavelengths.
**Maximum Efficient Frame Rate measured at 1064 nm for transitions between uncorrelated holograms generated by the Gerchberg-Saxton algorithm (i.e., many random phase values). The maximum rate is taken to be the speed at which the diffraction efficiency is reduced to ~90% of the steady-state diffraction efficiency. Higher speeds are possible with further reductions in efficiency. Maximum speed reported for holograms pre-downloaded to board.
***Once downloaded to the board, these holograms can be accessed in any order at high speed using hardware-implemented Overdrive calculations.
Our approach to SLMs has always been to start with the needs of the application and design from there. Most manufacturers start with a backplane designed for the display industry and then repurpose it as a SLM. Because we design our devices from the ground up, we’re able to achieve speeds and sizes that exceed anything in the display industry.
Dr. Doug McKnight
VP of Research & Development
Science, vol. 365, no. 6453, Aug. 2019, doi: 10.1126/science.aaw5202
Optical Trapping and Optical Micromanipulation XVI, San Diego, United States, Sep. 2019, p. 3, doi: 10.1117/12.2528558