Technology

Magnetic Actuation Principle

The MEMS mirrors are actuated at their mechanical resonant frequency. The maximum intrinsic silicon material gain is used, to obtain the widest possible scanning angle at an ultra-low power consumption level.

MEMS mirror actuation does not use gearing effects or any other mechanical contact-based effects. It uses an innovative fatigue-free magnetic actuation: en electric current flowing on the mirror itself, under a magnetic field, induces mechanical displacement, advanteagously used for optical scanning.

Key Actuation Characteristics :

  • CMOS-compatible actuation voltage (< 3V)
  • Very high-frequency operation (up to 50kHz)
  • Large scanning angle with low power consumption

mirror-fig3b

Unique Modeling & Design Expertise

Lemoptix has developed unique expertise in the areas of the mechanical and electrical design of MEMS scanning mirrors, magnetic actuation optimization and mirror optical properties. These in turn enable a high scanning frequency, a large scanning angle and high shock resistance, which are essential requirements for industrial and consumer applications alike.

MEMS Scanning Mirror Specifications
(examples)

MEMS chip size

(incl. packaging)

 Mirror size

Scanning

frequency

Scanning amplitude

(optical angle)

 Mirror flatness
 Shock resistance
2.6 x 3.8 mm 1 x 1 mm
 4 kHz
 60 degrees
 50 nm
 2'000g
2.6 x 3.8 mm 1 x 1 mm 20 kHz 40 degrees 50 nm 20'000g

Fully Hermetic Optical MEMS Packaging

Lemoptix has developed unique and proprietary fully hermetically packaged MEMS scanning mirror technology. Packaged MEMS devices are a key requirement for high volume / low cost manufacturing, generating a high fabrication and assembly yield.

Lemoptix packaging is done on wafer-level scale, meaning that thousands of devices are protected at once. Furthermore, in order to optimize the optical characteristics, the transparent packaging is coated with Anti-Reflective coating. Lemoptix packaged MEMS scanning mirrors are therefore totally protected from:

  • manipulation damages
  • humidity
  • dust and particle contamination

The packaging provides a complete and long-tern protection of the moving mechanism and therefore considerably increases the reliability of the system.

 packaging-proof

Reflective Surface

To ensure high light reflectivity of the MEMS scanning mirror, the devices are coated with highly reflective material. Due to the unique characteristics and flexibility of Lemoptix's fabrication process, Aluminum, Gold or Silver materials can be coated, depending on the requirements for the light wavelength.

Depending on materials and wavelength, the reflectivities are:

  • more than 90% in the visible range (from 400nm to 700 nm)
  • more than 95% in the Infra-Red domain (from 700 nm to few μm)