Based
on the advances in ARIMEMS fabrication technology which allow
independently controlled vertical combdrive sets, various examples of two-axis
MEMS optical scanners have been demonstrated and published recently.
SEM
micrograph of a two-axis scanning micromirror which
is not utilizing a gimbal design to achieve 2DoF rotation.
As a result, significantly higher frequencies of operation
are achievable for both axes.
The
gimbal-less device does not require any isolation methodology,
making its fabrication significantly less complex and thereby
less costly.
Measurements of a typical ARIMEMS-based gimbal-less 2D MEMS optical scanner.
SEM
micrograph of the most recent generation of the two-axis
scanning micromirror which is not utilizing a gimbal
design to achieve 2DoF rotation. As a result, the device
achieves 20 degrees of static optical deflection for
each axis with lowest resonant frequency for both
axes above 5 kHz. The mirror has a 0.6 mm diameter.
The entire device is monolithic single crystal silicon,
optically smooth and flat.
A
closer look at the micromirror and four linkages which
attach the micromirror to the 4 rotational actuators.
The linkages allow two degree of freedom rotation of
the mirror and also provide a gain of up to 3:1 between
actuator rotation and mirror rotation by properly choosing
the lenghts of the arms on either side of the compliant
torsional loops.
