Laser Beam Scanning

Laser Beam Scanning

MEMS ScanAR technology enables fast development of high-performance Augmented Reality glasses through a reference design and a manufacturing ecosystem.

STMicroelectronics is an industry leader in MEMS technologies and has demonstrated a strong expertise in developing sensors and actuators for decades. ST industrializes a broad range of MEMS actuators based on several technologies including thermal, electrostatic, electromagnetic, and piezoelectric devices and shipped more than 5 billion units over the past 20 years.

ST introduced MEMS micromirror devices by leveraging its extensive experience in MEMS technologies to design, develop and manufacture micro-electro-mechanical devices and electronic control systems to accurately and precisely rotate reflective surfaces along rotational axes.

MEMS micromirror solutions are typically used in laser beam scanning systems (LBS) to project visible images or infrared patterns. These solutions work by deflecting laser beams emitted from laser diodes to project images onto the required field of view. The beam deflection is generally performed using a combination of two mirrors rotating on perpendicular axes.

ST’s MEMS micromirror solutions combines MEMS micromirrors with the dedicated electronic components to build a complete LBS system. This portfolio includes:

  • MEMS micromirrors, either based on single- or dual-axis architecture, for visible or invisible (IR) projection.
  • MEMS micromirror driver ICs to ensure the accurate control of mirror positioning.
  • A Laser Diode Driver (LDD) specifically developed for Augmented Reality (AR) applications, which require low-power, high-resolution visible projection systems.

ST provides a one-stop-shop solution for laser beam scanning systems, including semiconductor technologies, products and reference designs. It enables a broad range of applications that go from visible projection for Augmented Reality and Mixed Reality (MR) applications, to IR projection for LiDAR and 3D sensing.

 

 

 

A complete solution for Augmented Reality applications

In AR and MR applications, the LBS system creates an image by scanning RGB laser beams onto the MEMS mirrors and modulating the laser beams at each pixel. This solution brings several benefits compared to its competitive technologies:

  • Extended depth of field
  • High persistency and low latency
  • High brightness, ideal for smart glasses
  • Scalable field of view
  • Compactness and power efficiency
  • Light weight for the overall optical light engine

 

ST introduced a new family of products called MEMS ScanAR, specifically designed for Augmented Reality applications, focusing on increasing performance while decreasing size, weight and power consumption. The MEMS ScanAR family includes the MEMS micromirrors and the associated electronics to drive the mirrors and laser diodes.

Additionally, to ensure a faster and a swifter integration cycle, ST developed a complete reference design based on the MEMS ScanAR components. The reference platform focuses on the application by providing key tools to enable development of the smart glasses. This reference design is also adaptable to the know-how and needs of each of our customers.

The first generation of the reference design offer the following benefits:

  • Crisp image with a resolution of 800 x 600 pixels and a refresh rate of 60 Hz
  • Extended field of view
  • An ultra-compact optical engine with a size < 0.75 cc
  • High brightness: > 1000 cd/m² (at the eye and dependent on the specific waveguide design)

 

ST and the LaSAR Alliance

In October 2020, ST and other leading technology developers, suppliers and manufacturers decided to join forces and collaborate to develop and accelerate AR smart-glasses solutions. Founding members in the LaSAR Alliance include Applied Materials, Dispelix, Mega1, and Osram, in addition to ST who envisioned and created the Alliance concept. The Alliance is focused on meeting the technical challenges required for all-day wearable smart glasses by creating an ecosystem that includes companies developing technologies, components and solutions, based on laser beam scanning (LBS), to provide Augmented Reality (AR) and  Mixed Reality (MR) device manufacturers with key foundational elements necessary to bring products to market. The goal is to facilitate the development of glasses solution that will balance a small, light-weight form factor and extremely low-power operation with good FoV (Field-of-View) and a large eyebox. The founding members coalesced around the recognition that near-to-eye displays based on ST-developed LBS solutions have demonstrated the potential to meet all these requirements.

 

 

 

Leveraging this ecosystem, ST and its partners have the ambitious goal to rapidly expand the membership of the Alliance to further the development, availability, and support of all key technology elements for rapid creation, adoption, and volume production of AR-enabled smart glasses applications.  

In January 2021, at CES, ST demonstrated a proof-of-concept smart glasses based on ST’s first-generation MEMS ScanAR reference platform. This proof-of-concept demonstration the capability of ST and several of the LaSAR alliance partners to provide a complete solution for AR eyewear applications. This demonstrator was achieved by close collaboration with several of the Alliance partners, in particular waveguides from Dispelix and an ultracompact laser diode module from OSRAM. The result is a crisp, 30-degree Field-of-View and large eye box image.

 

ST-published papers on Laser Beam Scanning

2021

A novel closed-loop architecture for accurate micromirror trajectory control in linear scanning MEMS-based projectors.
P. Frigerio, R. Tarsi, L. Molinari, G. Maiocchi, A. Barbieri, G. Langfelder – SPIE.Photonics West, SPIE OPTO, March 2021
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Compact and innovative laser beam steering optical engine for smart glasses applications.
A. Domnits, S. Erlich, D. Sharon, E. Roth – SPIE.Photonics West, SPIE OPTO, March 2021
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Electro-mechanical validation of a resonant MEMS mirror with PZT actuation and PZR sensing.
G. Mendicino, M. Merli, R. Carminati, N. Boni, A. Opreni, A. Frangi – SPIE.Photonics West, SPIE OPTO, March 2021
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Modeling and experimental verification of the impact of noise sources on projection accuracy of MEMS linear micromirrors for raster scanning applications.
P. Frigerio, A. Barbieri, M. Zamprogno, G. Langfelder – SPIE.Photonics West, SPIE OPTO, March 2021
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Multiple MEMS mirrors synchronization techniques, modeling, and applications.
G. Amor, E. Roth, D. Sharon, N. Gorelik, S. Kinstlich, S. Nagola – SPIE.Photonics West, SPIE OPTO, March 2021
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Quasi-static PZT actuated MEMS mirror with 4x3mm2 reflective area and high robustness.
N. Boni, R. Carminati, G. Mendicino, M. Merli,  – SPIE.Photonics West, SPIE OPTO, March 2021
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