Biomedical Engineering Reference
In-Depth Information
Microsope
Reimaging and
beam expansion
optics
Quarter-wave
plate
Reimaging and
beam expansion
optics
Femtosecond
laser
Beam
scanner
Polarizing
beam splitter
Deformable
mirror
FIGuRE 11.2
Basic.coniguration.for.an.adaptive.optics.system.placed.ater.the.scanning.optics.
Reimaging and
beam expansion
optics
Beam
scanner
Microscope
Reimaging and
beam expansion
optics
Quarter-wave
plate
Reimaging and
beam expansion
optics
Femtosecond
laser
Deformable
mirror
Polarizing
beam splitter
FIGuRE 11.3
Basic.coniguration.for.an.adaptive.optics.system.placed.before.the.scanning.optics.
system.before.reexpansion.and.reimaging.onto.the.back.aperture.of.the.objective..his.would.appear.to.
be.a.more-complex.coniguration,.but.as.will.be.discussed.later,.there.are.some.practical.advantages.in.
some.cases.for.such.a.setup..It.should.be.noted.here.that.a.number.of.users.have.demonstrated.that.both.
methods.work.
Before.discussing.which.coniguration.is.most.suitable.for.a.speciic.imaging.system,.an.alternative.to.
polarization.coupling.is.considered..In.the.two.systems.described.earlier,.the.beam.hits.the.AO.element.
at.normal.incidence.but.an.alternative.route.is.to.mount.the.element.at.an.angle.such.that.the.incoming.
and.outgoing.beams.do.not.coincide.(Chaigneau.et.al..2011)..Depending.on.the.space.available.and.the.
size.of.the.mirror.and.associated.optics,.the.mirror.may.be.placed.at.45°.to.the.incoming. light.beam.
or.at.smaller.angles..he.disadvantage.of.using.the.AO.at.this.angle.is.twofold..First,.the.travel.avail-
able.from.the.mirror.is.reduced.by.a.factor.of.√2.(at.45°).and.second,.the.actuators.on.the.mirrors.alter.
the.light.beam.in.diferent.manners.in.the.long.and.short.axis..he.clear.advantage.is.that.few.optical.
