Biomedical Engineering Reference
In-Depth Information
he.angular.magniication.is.given.by.the.reciprocal.of.the.linear.magniication:
1
F
F
1
2
.
M
=
= −
.
(9.3)
a
M
Relay.telescopes.utilize.two.relective.mirrors.instead.of.two.lenses.following.the.same.principles.as.
in.the.transmissive-type.relay.telescopes..he.linear.magniication.and.the.angular.magniication.are.
shown.as.in.Equations.9.2.and.9.3.
Transmissive-. and. relective-type. relay. telescopes. have. their. own. pros. and. cons.. Optical. designers.
need.to.decide.the.type.of.relay.telescope.to.be.used.for.pupil.conjugation.based.on.the.system.require-
ments.and.overall.system.performance.
Table. 9.1. provides. general. guidelines. for. choosing. relective. or. transmissive. relay. telescopes. for. an.
AO. biological. imaging. system.. Typically,. commercial. of-the-shelf. components. are. used. to. construct.
an. AO. microscope. to. reduce. the. cost. in. scientiic. experiments.. Quite. oten,. transmissive. lenses. and.
associated. optical. mounts. tend. to. have. more. options. than. those. of. relective. elements.. To. have. the.
required.optical.clearance.for.the.light.beam.in.an.of-axis.relective.telescope.and.to.minimize.optical.
aberrations,. relective. mirrors. with. longer. focal. lengths. are. typically. used. compared. to. transmissive.
telescopes..When.smaller.focal.length.optics.are.chosen.for.transmissive.telescopes,.the.optical.system.
becomes.more.compact..hey.could.be.signiicant.if.the.available.space.is.limited..Another.advantage.of.
transmissive.relay.telescopes.is.that.the.optical.alignment.is.more.forgiving.than.in.relective.telescopes.
FIGuRE 9.3
A.relective.relay.afocal.telescope.
TABlE 9.1
Comparison.of.Transmissive.and.Relective.Relay.Telescopes
Transmissive
Relective
Components.availability
More.choices
Fewer.choices
Space.constraints
Compact
Need.more.space
Alignment
Less.sensitive
More.sensitive
Light.budget
More.loss.per.component
Less.loss.per.component
Ghost.images
Yes
No
Background.noise
More
Less
Multiple.wavelengths
Chromatic.aberrations
No.chromatic.aberrations
Pupil.conjugate
Yes
Normal
DM.compensation
Point-to-point
Quasi.point-to-point
