Biomedical Engineering Reference
In-Depth Information
mode 2 - tip
mode 3 - tilt
Wavefront measurement
- Zernike mode representation
- specimen: optical fibre immersed into oil
- objective lens: Zeiss 20x, 0.5 N.A.
- condensor lens: Zeiss 40x, 0.6 N.A. Korr
- scan range 100
μ
m
×
100
μ
m
4
2
0
̶
2
̶
4
mode 4 - defocus
mode 5 - astigmatism
mode 6 - astigmatism
mode 7 - coma
2
1
0
̶
1
̶
2
mode 8 - coma
mode 9
mode 10
mode 11 - spherical(1st)
mode 12
mode 2 - tip
mode 3 - tilt
Wavefront simulation
- Zernike mode representation
- model for an optical fibre
consisting of a single cylinder of
uniform refractive index
4
2
0
̶
2
̶ ̶
4
mode 4 - defocus
mode 5 - astigmatism
mode 6 - astigmatism
mode 7 - coma
2
1
0
̶
1
̶
2
mode 8 - coma
mode 9
mode 10
mode 11 - spherical(1st)
mode 12
FIGuRE 6.8
Optical.iber.specimen..Representation.of.the.Zernike-mode.amplitudes.of.the.aberrated.wavefront.
when. the. optical. iber. is. imaged.. Experimental. results. from. the. interferometric. wavefront. measurements. (top).
and.simulation.results.for.a.cylinder.of.uniform.refractive.index.(
n
c
.=.1.49).embedded.in.oil.(
n
0
.=.1.518).(bottom).
Zernike.mode.variations.across.the.ield.of.view.are.reproduced.by.the.simulation..here.are.deviations.
from.the.simulation.for.some.modes.in.the.top.let.corner.of.the.iber.(for.instance,.visible.in.mode.5)..his.
was.due.to.total.internal.relection.efects.close.to.the.edge.of.the.iber,.which.caused.delection.of.inten-
sity.out.of.the.pupil,.which.in.turn.triggered.problems.for.the.Zernike-mode.itting.for.these.particular.
