U.D. Zeitner Fraunhofer Institut für Angewandte Optik und Feinmechanik

Jena

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

1. Introduction

NGC 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--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 m

icro

op

tics

(atomic size) light sources

optical elements optical effects

Effects of Size-Scaling

1mm 100µm 10µm 1µm 100nm

refraction diffraction

influence of physical effects on optical functions

is changing if characteristic feature sizes are scaled

focus: f=5mm

125µ

m

structure size

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 mathematics Analytical 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 functionality

different 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

2009 ITRS

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-map vanishing versatility for

other applications

Typical Optical Surfaces and Contours

Contours Profiles

lens prism beam shaper

binary grating blazed grating

subwavelength gratings

complex surface

profiles

>>

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>>

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characteristic

detail

Courtesy of E.-B. Kley