Download pdf - Stereoscopic Hologram - KNU3dot.knu.ac.kr/.../05/Talk5_Stereoscopic-Hologram.pdfStereoscopic hologram has a great potential to display large field through a narrow viewing windows

3 Dimensional Optical Technology 3DOT

Stereoscopic Hologram

Joonku Hahn

Kyungpook National University

http://www.knu.ac.kr/bbs/newmain/index.jsp


Outline:

1. Introduction

- Basic structure of holographic display

- Wigner distribution function

2. Design of ‘Stereoscopic Hologram’

- Optical design concept

- Viewing window

- Spatial light modulator

3. Examples of ‘Stereoscopic Hologram’

- Holographic display with a large-scale SLM

- Projection-type holographic display

- Head-mounted holographic display

4. Summary

1



2

1. Introduction

Available structure of holographic display

Electrically

addressable

Spatial Light

Modulator

Coherent

Light

Source

Optics Optics Observer Screen Optical

filter

Scanner Optically

addressable

Spatial Light

Modulator

(optional) (optional)


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3

1. Introduction

f

duM

p

Np

p

p

ap

ap

u

v

v

uW

vW

Transfer lens

Focal plane

0 order

diffraction

-1 order diffraction

on v-axis

+1 order diffraction

on v-axis

Local viewing angle

Spherical phase

resulting from

Amplitude contour

by sinc function

Pixels of SLM

d f

,c c

Central direction of

local viewing angle

2 22 Area of image Numerical Aperture wavelength .u v u vN M W W

Space-bandwidth product

J. Hahn, H. Kim, Y. Lim, G. Park, and B. Lee, Optics Express 16, pp. 12372-12386, (2008).

2 2Data capacity Area of screen Field of view wavelength Color depth

Space-Bandwidth Product

Data capacity



4

Wigner distribution function

x

v

x

v

After a Fresnel transform After a Fourier transform

x

v

The area in the Wigner distribution function is equal to the space-bandwidth product.

A. W. Lohmann, R. G. Dorsch, D. Mendlovic, Z. Zalevsky, and C. Ferreira, J. Opt. Soc. Am. A 13, 470-473 (1996).

1. Introduction



5

Hologram plane

Viewing window plane

x

y

u

v

Definition of the planes in holographic display

1. Introduction



6

Holographic Stereogram vs. Stereoscopic Hologram

Holographic

Stereogram

Stereoscopic

Hologram

1. Introduction

Viewing window plane Hologram plane



7


1.8m

20inch

10inch

View volume defined

by 4K-resolution hologram 40inch

View volume defined

by 2K-resolution hologram

View volume defined

by 8K-resolution hologram

Stereoscopic Hologram

Transverse resolution at screen

0.11

Width of viewing window at pupil of eye

1.8 8.2 @ 0.5VW

p mm

w m p mm m



8

Hologram plane

Viewing window


Basic geometry of stereoscopic holographic display



9

Large-aperture SLM

Viewing windowLight source

Hologram plane


Display with a large-aperture SLM



10


Viewing window

Spot size of undiffracted light needs to be small enough for fear of disturbing the signal

which is modulated by spatial light modulator.



11

Small-aperture SLM

Viewing window

Light source

Projection optics

with a pair of parabolic mirrors Hologram plane


Projection-type display

‘Real image’



12


Types and properties of SLM

Liquid crystal display

(LCD) modulator

Digital micro-mirror device

(DMD) modulator

Acousto-optic modulator

(AOM)

Liquid crystal on Silicon

(LCoS) modulator

Amplitude-only modulation

Phase-only modulation

-1 1

i

-i

Re

Im

Full-complex modulation

-1 1

i

-i

Re

Im

Typical characteristic

of liquid crystal device

-1 1

i

-i

Re

Im

-1 1

i

-i

Re

Im



13

f

1( )G f

maxf maxf

f

2 ( )G f

maxf maxff

3( )G f

maxf maxf

f

0 ( )G f

maxfmaxf

(a) (b)

(c) (d)


Off-axis complex hologram encoding with amplitude-only modulation

C.-Y. Hwang, K.-S. Kim, B.-R. Lee, S. Oh, H. Kim, and J. Hahn, “Off-axis complex hologram encoding with amplitude-only modulation,” Opt. Express

submitted.



14


0x

0y 5y

5x

SLM planeViewing

window plane

z

2x

2y

Focal plane

4x

4y

1d 2 1d f 3d 4d 5d

Image plane

1f 2f 3f

1x

1y

3x

3y

Structure for off-axis complex hologram encoding with amplitude-only modulation



15


Head-mount display

Light source

SLM

Viewing window Eyepiece

Hologram plane

‘Virtual image’



16

Optical design


Holographic display with a large-scale SLM

Layout



17

EYE Tracking Beamsplitter

Large-scale

Spatial Light Modulator

Array of Point Light Sources

Hologram Calculation

I/O ports

Main Control

Input Optics



Structure according to functions



Spatial light modulators

Input integrated optics

Motorized stages with

light sources array

Control boards Large-format beam splitter

18

1800mm500mm

182mm144mm

4.55deg

z

y

z=0

, ,in in inx y z , ,out out outx y z

z=-500mm z=1800mm





19

Light engines

Optics for projection

Holographic display

Viewing windows

Viewing windows

Parabolic mirrors

Mirrors

FT lenses

SLM

Projection-type holographic display


Optical design Layout



20

Collimators

Left part Right part

X-cube prism

Laser diode modules Red

Green

Blue Red

Green

Blue

Mirrors

FT lensesFilters

SLMs

SLMs

Collimators

X-cube prism

Laser diode modules

Laser diode module

Polarizer

PinholePlate spring

Objective lensCollimation lens

Adjustable tube

(a)

Red Green Blue

Projection-type holographic display

Light engine




21



10inch screen



22



Simulation Experiment

Focused

at the screen

Focused

0.9m away

from the screen



23

Head-mounted holographic display


Optical design

Layout



24

Control box

with light sources

Holographic display

for head-mounted application

Multimode optical fiber

Data cable

Multimode

optical fiber

Data cable

Beamsplitter

at viewing window Blue LED

Green LEDRed LED

Multimode

optical fiber

Control board





25


y-axis [mm]

x-ax

is [m

m]

Complex optical field on retina

-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

y-axis [mm]

x-ax

is [m

m]


-1 -0.5 0 0.5 1

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

Simulation Experiment

Red

(625nm)

Green

(528nm)

Blue

(462nm)

@1125mm @725mm @1125mm @725mm




26

4. Summary

Stereoscopic hologram has a great potential to display large field through a narrow

viewing windows.

Optical design of stereoscopic hologram has three possible geometries. The first

applies a large-aperture SLM and the second displays a real image of the SLM. The

last displays a virtual image of the SLM.

We succeeded in constructing several interesting systems under the cooperation

with Prof. Kim’s group in Korea University.

I N T E G R A T E D P H O T O N I C D E V I C E S & S Y S T E M S L A B

3 Dimensional

Optical

Technology
