What
is Adaptive Optics?
Adaptive Optics
(AO) is the science of adapting an optical system to compensate for
distortions in the path of light from an image that we
wish to view.
Imagine your eyes and your glasses, if you wear glasses. Over
time, you may go from not needing glasses to needing them, and then you
may have to change from one
perscription to another as you need to compensate for continued changes
in your eyes.
So, you change your glasses, perhaps every year or so, to compensate
for the way your eye
(your optics) change in the way they bend light. This is a very
simple view of
what AO is all about. However, ususally in AO, the time between
required changes in the optics is measured in milliseconds not years,
and we
don't replace the optics, we actually modify them in real time.
Also, in this example, the optics of your eye are changing and we are
compensating for that. Usually, in astronomical AO, we are
compensating for changes in the atmosphere which also act like lenses
and change constantly with wind, temperature, etc. But, you get
the idea.
AO in
Astronomy
As we said, in astronomy, the changing
conditions, for which we are compensating, are generally
conditions in the
atmosphere, which interfere with our ability to see objects in the
sky. Also, these
changes
take place over milliseconds rather than years. The time scale is
different, but the idea is the same.
When we are changing our optics every millisecond, we don't
put in new lenses to accomplish the change, we must somehow, actually
change the optical components themselves, in real time.
AO Concepts
What are we trying to correct for?
How do we correct it?
What problems do we face?