Deformable mirror
A deformable is an example of an optic that evolves dynamically in
response to external commands. Arroyo currently supports a simple
model for the temporal evolution of a deformable mirror. In this
model, each actuator moves from its current location towards its
commanded location with constant linear velocity. If the actuator
reaches the requested location before a new command is issued, it
stops instantaneously. If it does not, the actuator instantaneously
changes direction and begins to move towards the new commanded
location with constant velocity. The actuator velocity is a parameter
that may be specified by the library user. The mirror aperture is a
template parameter, and may be chosen from one of several shapes.
Currently the only actuator influence function supported by Arroyo is
the pyramidal influence function. Hysteresis has been neglected as
well.
Here is a set of movies showing a plane wave incident on a 7x7
actuator deformable mirror with a circular aperture. The plane wave
had an electromagnetic wavelength of 1 micron. In these movies, the
actuators were commanded to move cyclically between +/-.5 microns.
New commands were issued every 10 milliseconds. Three different
actuator velocities were chosen for this demonstration: 300, 100, and
33 microns/sec, and the resulting plane waves are displayed from left
to right. The intermediate value is the one for which the mirror
completes its move just as a new command is issued. The two other
values correspond to actuator velocities 3 times faster and 3 times
slower than this critical value.
Single actuator pattern
Piston pattern
Waffle pattern
Plus pattern
Cross pattern
This demonstration was generated using the program deformable_mirror_verification, which
is included in the Arroyo distribution.