Course

HO - Holography


PDF Course Catalog Deutsche Version: HO

Version: 1 | Last Change: 19.09.2019 15:07 | Draft: 0 | Status: vom verantwortlichen Dozent freigegeben

Long name Holography
Approving CModule HO_BaET
Responsible
Prof. Dr. Stefan Altmeyer
Professor Fakultät IME
Level Bachelor
Semester in the year summer semester
Duration Semester
Hours in self-study 78
ECTS 5
Professors
Prof. Dr. Stefan Altmeyer
Professor Fakultät IME
Requirements mathematics:
- vector calculus
- complex numbers
- Fourier transform

physics / optics
- paraxial optics
- wave optics
Language German
Separate final exam Yes
Literature
Ackermann, Eichler: Holography (Wiley VCH)
Goodman: Fourier Optics (Roberts and Company Publishers)
Lauterborn, Kurz: Coherent Optics (Springer)
Final exam
Details
As long as the number of participants is not too high, an oral examination is preferred over written exams.

Lowest competence level checked is knowledge. Questions could adress the definition of thick and thin gratings, the formulation of the grating equation for thick gratings for different angular situations, the numbers of achievable diffraction efficiency in amplitude- and phase holograms.

The next competence level is related to skills. Examination could be done by the task to find out the position of the different diffraction orders when a holographics setup is given, the diffraction efficieny of the different diffraction orders of a thin phase hologram are calculated, the requirements on temporal coherence in a holographic setup is used to find the maximum allowed linewidth of the laser in use, or to explain, what details have to be considered, when a holographic setup has to be built.

The highest competence level adressed is methodical expertise. It can be checked by a real world task: E.g. the design of a holographic setup to record digital holograms for a technical 3D contour measurement, the draft of an algorithm to calculate a digital hologram, the design of a procedure to copy holohrams, so that they can be reconstructed with white light instead of lasers. In a guided discussion or guided calculation it can be found out easily, if the underlying principles are understood and can be applied proactively, if intellectual transfer is made and if there is sufficient overview.
Minimum standard
Correct answer of at least 50 % of the questions
Exam Type
As long as the number of participants is not too high, an oral examination is preferred over written exams.

Lowest competence level checked is knowledge. Questions could adress the definition of thick and thin gratings, the formulation of the grating equation for thick gratings for different angular situations, the numbers of achievable diffraction efficiency in amplitude- and phase holograms.

The next competence level is related to skills. Examination could be done by the task to find out the position of the different diffraction orders when a holographics setup is given, the diffraction efficieny of the different diffraction orders of a thin phase hologram are calculated, the requirements on temporal coherence in a holographic setup is used to find the maximum allowed linewidth of the laser in use, or to explain, what details have to be considered, when a holographic setup has to be built.

The highest competence level adressed is methodical expertise. It can be checked by a real world task: E.g. the design of a holographic setup to record digital holograms for a technical 3D contour measurement, the draft of an algorithm to calculate a digital hologram, the design of a procedure to copy holohrams, so that they can be reconstructed with white light instead of lasers. In a guided discussion or guided calculation it can be found out easily, if the underlying principles are understood and can be applied proactively, if intellectual transfer is made and if there is sufficient overview.

Learning goals

Knowledge
Characterisitcs of a hologram, difference to photos, stereograms, 3D cinema etc.

thin gratings
grating equation
exposure of gratings
influence of angles
influence of polarization
diffraction efficiency of thin gratings
amplitude gratings
phase gratings

Holographic imaging equations
recording of a hologram
reconstruction of a hologram
interpretation of the different diffraction orders
location of the diffraction orders
inline and side band holograms

zone plates
inline zone plates
interference of spherical and plane wave
focal points as real and virtual images
white light reconstruction, dispersion, orthoscopic and pseudoscopic image
interpretation as angular grating with variable perio
off axis zone plates
interference of spherical and plane wave
shift of spherical wave: shift of zone plate
tilt of plane wave: ellipitical deformation
increase in spatial frequencies
separation of real and virtual image
applications: measurement of particles, injection system design, respirable sprays

basic properties of holograms
transition from elementary holograms to complex holograms
dispersion in holograms
reconstruction with different wavelengths
reconstruction with white light
blurring in non image plane hologra,s
viewbox
in dependence on the image depth
recording with high aperture objectives
diffusors for aperture stretching in near image plane holography
image plane holography and dispersion
coherence requirements of reconstruction
light source extension and lateral image precision
spectral pureness and axial image precision

copying holograms
contact copy
copy with image plane shift
coherence requirements in copy processes

thick gratings
definiton
Bragg condition
efficiency

classificaion of holograms
interferogram of two point sources
locations of equal phase and euqality in distance difference
classification
thick and thin holograms
on- and off-axis holograms
transmission and reflxion holograms
Fourier holograms

white light holograms
Benton's white light holograms
thin white light hologram
reduction of perspective to one dimension
methods for recording and reconstruction
print copying
application: EC card, ID card, product labelling
Denisjuk holograms
thick white light hologram
Lippmann's color photography
principle of spectral filtering
depth of field, spectral properties, luminosity
rennisance due to new materials: photopolymer
RGB Denisjuks
applications: head-up display, sensor holograms, autostereoscopic displays

multiplexing of holograms
angular multiplexing
wavelength multiplexing
share of index modulation
applications: low content displays, RGB Denisjuk holograms

digital holograms
phase conserving interference of spherical waves
restriction to amplitude or phase due to recording materials
phase freedon of image points
Gerchberg Saxton algorithms, iterative Fourier transform algorithms
calculation of digital stereograms
phas shifting spatial light modulators: LCoS displays
applications: Diffractice Optical Elements, holographic ruler, flexible digital optics,
cinematic holography and displays

if there is enough time in the semester:

coupled wave theory of Kogelnik to calculate the diffraction efficiency of thick holograms.

Skills
Judge advantages and drawbacks of different technical 3D technologies

Calculate efficiencies of thin gratings

Calculate types and positions of different diffraction orders in off axis holograms

Apply the principles to spatially move and tune the efficieny of the different diffraction orders

Calculate the depth of field in holograms an find required parameters for the light sources

Classify holograms and choose the right application specific one

Choose the right copy process for each application

Design holographic setups application specific

Calculate digital holograms
Expenditure classroom teaching
Type Attendance (h/Wk.)
Lecture 2
Tutorial (voluntary) 0
Special literature
keine/none
Special requirements
none
Accompanying material
lecture notes as downloadable file
Separate exam
none

Learning goals

Skills
align laser to optical axis

setup spherical and plane waves

plan foldes beam paths

align complex optical setups

balance optical paths in asymmetric setups

make and use a setup for Denisjuk holograms

make and use a setup for zone plates

make and use a setup for gratings

make and use a setup for off axis holograms

make and use a setup for rainbow copies

make and use a setup for digital holography with an LCoS display
Expenditure classroom teaching
Type Attendance (h/Wk.)
Practical training 2
Tutorial (voluntary) 0
Special literature
keine/none
Special requirements
none
Accompanying material
Instrcutions for the experiments as downloadable files.

Operating manuals for complex equipment as downloadable files.
Separate exam
Exam Type
working on projects assignment with your team e.g. in a lab)
Details
1) Written examination questions and complex calculations, which require to find a suitable
Ansatz, related to the experiment have to be prepared at home.

2) The homework is discussed with all participants at the beginning of the laboratory.
The underlying ideas of the experiments have to be explained at the beginning of the
laboratory and are discussed extensively.

3) Make the experiment alone in a team of two.
- Build up and adjust your own setup
- record and reconstruct holograms with this setup
Minimum standard
All written tasks must have been delt with.

The basic ideas of the experiment must have been understood.

All experiments must have been performed.

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