Biomedical Engineering Reference
In-Depth Information
brightness.decreases.with.the.increase.in.axial.distance,.adjust.the.micrometer.back.in.the.axial.direc-
tion.and.ind.the.location.of.the.pinhole.with.the.maximum.brightness.
9.8 Assembly Procedures for an Ao System
A.complete.AO.system.typically.involves.several.optical.paths.and.many.optical.and.optoelectrical.com-
ponents..It.is.strongly.advised.to.perform.the.system.assembly.in.a.systematic.way..It.is.recommended.
to.quickly.go.through.the.entire.alignment.procedure.to.verify.that.there.are.no.obvious.mechanical.
.problems—such.as.any.conlicts.or.narrow.spaces—and.there.are.suicient.ranges.for.adjustment..In.
addition,.exploring.the.alignment.tools.helps.to.make.sure.that.they.can.achieve.their.targeted.functions.
and. are. easy. to. use.. Operate. the. active. components. such. as. sources. and. detectors. before. integrating.
them.into.the.system..If.there.is.any.issue,.at.this.point.it.is.best.to.resolve.the.issue,.before.full.integra-
tion. and. alignment. of. the. component.. Once. all. major. initial. problems. have. been. resolved,. one. may.
proceed.with.a.more.careful.and.critical.ine.alignment.
.
1.. Measure. the. wavefront. errors. of. the. optical. components,. preferably. mounted. in. their. holders..
Optomechanical.mounting.may.cause.stress.and.thus.create.additional.aberrations..If.spare.parts.
are.purchased,.use.the.better-quality.components.
.
2.. If.the.wavefront.error.is.within.the.tolerance.of.the.components.speciications,.the.optical.design.
does. not. need. to. change.. Otherwise,. the. initial. optical. design. may. require. slight. modiication.
to. compensate. the. wavefront. errors. or. better-performance. optical. components. may. need. to. be.
repurchased.
.
3.. As.a.good.practice,.label.optical.components.on.the.sides.or.mounts.to.eliminate.any.confusion.
about.the.optic's.identity.
.
4.. Print. out. a. 1:1. ratio. optical. design. layout. and. place. all. the. components. on. the. optical. table. or.
breadboard.according.to.the.layout..Check.if.there.are.obvious.mechanical.conlict.issues.
.
5.. Center. all. optomechanical. adjustments. for. the. optical. components. initially. within. their. travel.
ranges.to.minimize.the.possibility.of.running.out.of.travel.during.alignment.
.
6.. Assemble. the. building. blocks—optical. subassemblies. such. as. relay. telescopes,. WFSs,. and. laser.
source.collimators—oline.
.
7.. Use.a.lat.mirror.in.place.of.the.DM..Build.the.optomechanical.mounts.for.the.DM,.so.that.the.lat.
mirror.and.DM.are.interchangeable.without.the.need.for.realignment.
.
8.. Establish.the.line.of.sight.or.optical.axis.with.a.collimated.alignment.laser.(quite.oten.used.as.an.
illuminator.laser.as.well).
.
9.. Install.beam.splitters.and.mirrors.in.the.beam.paths..Start.from.the.mirror.or.beam.splitter.fur-
thest.upstream.and.work.downstream..Adjust.the.tilt.of.each.mirror.so.that.the.line.of.sight.hits.
the.center.of.each.mirror.
.
10.. Start.installing.the.relay.telescope.furthest.upstream.and.work.downstream..he.speciied.loca-
tion.on.the.optomechanical.design.printout.can.help.to.place.the.relay.telescope.close.to.its.cor-
rect.positions..Adjust.the.lateral.position.and.the.tilt.of.the.subassembly.so.that.the.line.of.sight.is.
still.at.the.center.for.the.downstream.mirrors.and.hits.the.inal.target..Relay.telescopes.are.used.
to.relay.conjugate.planes.in.an.AO.system..he.lenses.in.the.relay.telescopes.are.one.focal.length.
away.from.the.pupil.planes..Set.up.a.pupil.camera.to.adjust.the.position.of.the.relay.telescope.so.
that.the.conjugate.planes.are.in.focus.
.
11.. Ater.installation.of.the.optical.elements.in.the.major.optical.paths.from.the.illumination.source.
to.the.science.imaging.samples,.install.the.other.functioning.optical.paths.involving. the.active.
optical.elements,.such.as.the.WFS.and.the.detector.
.
12.. Adjust.the.optical.subassembly.of.the.WFS.so.that.the.optical.beam.incident.to.the.WFS.is.well.
centered.and.perpendicular.to.the.lenslet.array..Check.the.image.on.the.pupil.camera.to.ensure.
