U.D. ZeitnerFraunhofer Institut für Angewandte Optik und Feinmechanik

Jena

Micro- and Nano-Technology...... for Optics

1. Introduction

Micro- and Nano-Technology...... for Optics

1. Introduction

NGC 6744NGC 6744

GAIA (ESA)launched in Dec. 2013

RVS

230mm

GAIA’s effective medium grating

Micro-Structured Optics in Nature

2µm

Nano-structures with anti-reflection properties on moth‘s-eyes

Lens-arrays as insects eyes

100µm

Colors of butterflies by diffraction gratings

4µm

Different Approaches

Nature Technology

!?!?

“Bottom-Up” “Top-Down”

Lithography

huge variety of high resolution structures

The field of micro-structured optics

1mm

1µm

10nm

10µm

100µm

100nm

characteristic feature size

micro-lenses, micro-prisms

lens-arrays,refractive beam-shaper

diffractive beam-shaper,Fresnel-lenses,diffraction gratings

effective media,sub-λ-gratings,photonic crystals,meta-materials

hybride elements

Size scale of micro-optical effects

Size-Scale of Optical Structures

1Å

1nm

1µm

1mm

1m

law of refraction and reflection

light diffraction

effective medium

spontaneous and stimulated emission

astronomic mirrors

lenses

micro-lenses

antireflection pattern, polarizers, phase retarder photonic crystals

miniaturized lenses

paraxial beam splitters

non paraxial beam splitter

spectroscopic gratings

mic

ro o

pti

cs

λλλλλλλλ

(atomic size) light sources

optical elementsoptical elementsoptical effectsoptical effects

Effects of Size-Scaling

1mm 100µm 10µm 1µm 100nm

refraction diffraction

influence of physical effects on optical functionsis changing if characteristic feature sizes are scaled

focus:f=5mm

125µm

Strukturgröße

artificial dichroitic materials

physical effect:effective material-properties

disturbing useful !

diffractive beam splitter

2µm

wire-grid-polarizer

Milestones of optical engineering

Maxwell

1831 - 1879

electromagnetic wave theory

Fresnel

1788 - 1827

wave theory of the light

Hertz

1857 - 1894

exp. confirm. of Maxwell

Fourier

1768 - 1830

Fourier expansion

Abbe

1840 - 1905

theory of opt. image

Basics in physics and mathematicsAnalytical and numerical

evaluation of physical optics

Personal Computer

Demands on micro- and

nanomachining

18

00

19

00

20

00

Fundamental understanding

of optics

Zuse

1910 - 1995

1941 1st calculator

Fabrication Technologies for Micro-Optics

common micro-optics fabrication methods are

• lithography (photo-, e-beam-, laser-)

• ultra precision micro-machining

• melting / reflow technology

• more elaborated technologies

different size and functionalitydifferent fabrication methods

for micro-optical components compared to classical (macro) optics

High resolution lithography

ASML-Stepper

Fabrication of microelectronic chips on Si-wafers

Lithography Roadmap

Lithography for Optical Applications

Lithography tools are developed for micro-electronics fabrication!

Demands of optics on lithography:

• arbitrary lateral contours (often radially symmetric)• several 100mm size of single elements with sub-micron features• thick substrates for elements with low wave-front error• non-planar substrates possible• …

steady development along semiconductor road-mapJJJJ

vanishing versatility for other applications LLLL

Typical Optical Surfaces and Contours

Contours Profiles

lens prism beam shaper

binary grating blazed grating

subwavelength gratings

complex surface profiles

>> λλλλ

< λλλλ

> λλλλ

>> λλλλ> λλλλ< λλλλ

characteristic detail

Courtesy of E.-B. Kley