ernst bernhard kley / [email protected] friedrich
TRANSCRIPT
1INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
Ernst Bernhard Kley / [email protected] University- Jena, Jena, Germany,
and Fraunhofer-Institute, Jena, Germany
Micro and nanooptics
ResearchUniversity
Development, application, systemsFraunhofer Institute
DOE Gratings (dispersive, coupler/combiner, mirrors)Wave guide opticsEffective mediaPolarization, birefringencePlasmonicsMetamaterials
2INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
3INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
500nm period grating
max. writing field: 300mm x 300mmresolution: <50nmaddress grid: 1nmoverlay accuracy: 12nm (mask to mean)
etching toolsIBERIBERIE ICP RIE
Our technology
E-beam writerVistec SB350 OS
4INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
200mm x 200mm grating, 230mm x 230mm substrate1µm period
Grating sizes
Sizes available6” x 6”9” x 9”12” x 4”(20” x 20”)
5INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
Reflective wave-front measurement(1µm period grating + technology, Littrow-Mount)
-5nm
+8nm
109mm
80m
m
+ 6.3nm
- 6.6nm
19mm
50m
m
<1.1 nm1.4nmrms<10.3 nm12.8nmPVplacementwavefront
<2.2 nm2.7nmrms<10.3 nm12.8nmPVplacementwavefront
grating wave front gradient up to 5nm/mm period uniformity < 40pm
6INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
Wavefront gradientcaused by the grating
20mm
Gradient up to 5nm/mm
Grating line qualitywidth variation
6” mask blankResist FEP 171
120mm x 120mm: ± 5nm100mm x 100mm: ± 3nm
line width variation
line edge roughnessdepending on writing strategy
6 – 10nm
Uniformity of diffraction efficiencyDepends on- design tolerances- technology applied
7INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
Reflection gratingsbest off
~ 1040nmperiod 1040nm
0R-1R
Optimized for combining
TE 99.4%TM 99.6%Combining efficiency 99%
TE 99.9%
typically values 97 – 99% (depending on design and technology)
Optimized for TE
8INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
Transmission gratings
Fabry-Perot effect
Moth Eye effect
Small periods Fresnel reflection
effective medium grating
embedding
2 ways for anti reflection (AR)
9INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
Transmission gratings
= 1040nm, period = 600nm, Littrow angle 62.5°
TE-Efficiencydesign 100%measured 98%
TE-Efficiencydesign > 99%measured 97%
TE-Efficiencydesign 93%not fabricated
Classical grating AR by Fabry Perot AR by effective media
2 ways for anti reflection (AR)
10INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
0% damage probability [J/cm2]
5.5
0.65
0.7
10
6.52.21.731.623.3 (5.5)8ps (IAP)
1.5150fs
273580 (200)8ns
250360170ns
AR RGHRTG(un)treatedsubstrate
Gold-coated
stoch.AR
determ.AR
Damage
11INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
Spectrometer grating for the Gaia missionof European Space Agency
Gaia (Dec. 2011)
-1E9 Stars- Magnitude: 22.5-20
Distance measurement by read shift measurement
Radial Velocity Spectrometer
Spektral range: 847-874 nm
Grating
12INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
period: 3310nmwavelength: 850nmTE, TM efficiency: >83%Polarization sensitivity: < 5%back side reflectivity <0.3%
Results for the Gaia grating
e-beam writing time for 210mm x 155mm- diffraction grating: 36 -75 h (depends on design)- AR-Grating: 10 h
500nm period, 1200nm depth
pattern geometry optical equivalent
13INSTITUTE of APPLIED PHYSICSFriedrich-Schiller University Jena
Wave-Front Full Grating Area 155mm x 205mm
transmitted wave-front(tilt, defocus removed)
P-V: 81nmRMS: 8.4nmRMS: < 5nm (on quality area)
x
y
1st diffraction order
grating area:
wave front on Ø60mm < 5nm