Liquid crystal on silicon
LCoS initially was developed for projection televisions, but has since found additional uses in wavelength selective switching, structured illumination, near-eye displays and optical pulse shaping.
[6] A common voltage for all the pixels is supplied by a transparent conductive layer made of indium tin oxide on the cover glass.
[9] A joint venture between Hughes Electronics and JVC (Hughes-JVC) was founded in 1992[10] to develop LCLV technology for commercial movie theaters under the branding ILA (Image Light Amplifer).
The SXRD technology was used in Sony's high-end home theater projectors, and it quickly gained a reputation for its exceptional picture quality.
JVC introduced an updated D-ILA technology in 2006, which eliminated the need for a polarizing filter, resulting in a brighter and more vibrant image.
LCoS projectors have continued to evolve, with manufacturers introducing features like 4K resolution and HDR (High Dynamic Range) support.
The white light is separated into three components (red, green and blue) and then combined back after modulation by the 3 LCoS devices.
Both Toshiba's and Intel's single-panel LCOS display program were discontinued in 2004 before any units reached final-stage prototype.
Forth Dimension Displays continues to offer a Ferroelectric LCoS display technology (known as Time Domain Imaging) available in QXGA, SXGA and WXGA resolutions which today is used for high resolution near-eye applications such as Training & Simulation, structured light pattern projection for AOI.
Citizen Finedevice (CFD) also continues to manufacturer single panel RGB displays using FLCoS technology (Ferroelectric Liquid Crystals).
[17] Whilst initially developed for large-screen projectors, LCoS displays have found a consumer niche in the area of pico-projectors, where their small size and low power consumption are well-matched to the constraints of such devices.
At CES 2018, Hong Kong Applied Science and Technology Research Institute Company Limited (ASTRI) and OmniVision showcased a reference design for a wireless augmented reality headset that could achieve 60 degree field of view (FoV).
Typically, a large number of phase steps are used to create a highly efficient, low-insertion loss switch shown.
LCoS-based WSS, however, permit dynamic control of channel centre frequency and bandwidth through on-the-fly modification of the pixel arrays via embedded software.
This is advantageous from a manufacturability perspective, with different channel plans being able to be created from a single platform and even different operating bands (such as C and L) being able to use an identical switch matrix.
[30] Structured light using a fast ferroelectric LCoS is used in 3D-superresolution microscopy techniques and in fringe projection for 3D-automated optical inspection.
One of the interesting applications of LCoS is the ability to transform between modes of few-moded optical fibers[31] which have been proposed as the basis of higher capacity transmission systems in the future.
Similarly LCoS has been used to steer light into selected cores of multicore fiber transmission systems, again as a type of Space Division Multiplexing.
