StructureMethodology and Facts– topics of the competitions– organisation and sponsors– participation and statistics– LIDT measurement methods

www.uni-hannover.de/.../tdf/i_37_laser.jpg

www.uni-hannover.de/.../tdf/i_37_laser.jpg

Review of Results– detailed analysis considering

processes and materials– general trends for wavelength

and pulse duration

Conclusions– observed general trends– LD Competition 2019

damage stress induced @ 143 J/cm2, 200μm, 14 ns, Nd:YAG-laser 1.064 μm

Summary on Laser Damage Competitions

Experiment 2008: HR 1.064 nm, 0°, ns-regime, 35 samplesExperiment 2009: HR 780 nm, 0°, LIDT, fs-regime, 27 samplesExperiment 2010: AR 351 nm, 0°, LIDT, ns-regime, 29 samplesExperiment 2011: HR 193 nm, 0°, LIDT, ns-regime, 12 samplesExperiment 2012: PB 1.064 nm, 57°, ns-regime, p-pol., 26 samplesExperiment 2013: PB 1.064 nm, 57°, ns-regime, s-pol., 31 samplesExperiment 2014: BP 1.064 nm, n. 0°, ns-regime, 6 samplesExperiment 2015: BBHR ld 773 nm, 45°, ps-regime, 33 samplesExperiment 2016: BBHR ld 773 nm, 45°, fs-regime, 42 samplesExperiment 2017: HR 355 nm, 45°, p-pol, ns-regime, 35 samplesExperiment 2018: HR 1.064 nm, 0°, ns-regime, 33 samples

SPIE Vol. 7132, 2009

SPIE Vol. 7504, 2010

SPIE Vol. 7842, 2011

SPIE Vol. 8190, 2011

SPIE Vol. 8530, 2012

SPIE Vol. 8885, 2013

SPIE Vol. 9237, 2014

SPIE Vol. 9632, 2015

SPIE Vol. 10014, 2016

SPIE Vol. 10447, 2017

citations in viewgraphs according to list of references above

SPIE Vol. 10805, 2018

Laser Damage XL to L Laser Damage Competitions

Topics of the Competitions

Organisation and Sponsors

Organisation and Procedure– specifications of the competition published with LD-call– participants produce and send in their samples with outline including:

- cleaning method, deposition process, number of layers- employed materials (coating, substrate)- spectral data

– administrative officer at LLNL collects and labels (anonymous) samples– measurements performed and results reported by code during LD-Symposium – individual sample code provided to participant

→ anonymous and double blind experiment

RalucaNegresLLNL

Chris StolzLLNL

https://contactout.com/Raluca-Negres-11931279

https://lasers.llnl.gov/news/photons-fusion/2013/october

Christopher J. Stolz, Raluca A. Negres, “Ten-year summary of the Boulder Damage Symposium annual thin film laser damage

competition,” Opt. Eng. 57(12), 121910 (2018), doi: 10.1117/1.OE.57.12.121910.

Sponsors

Chris StolzRaluca Negres

Co-workersLIDT-testing andmeasurements

Sample Requirements, Testing Laboratories

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018Coating type HR HR AR HR Polarizer Polarizer FP HR HR HR HRWavelength (nm) 1064 786 355 193 1064 1064 1064 773 ± 50 773 ± 50 355 1064Pulse Length (ns) 5 0,00018 7,5 13 10 10 3.5 & 18 0,15 0,00004 5 3Repetition rate (Hz) 10 1000 10 100 20 20 10 500 500 10 5Reflectivity (%) >99.5 >99.5 >97 >99 >99.5 >99.5 >99.5 >99.5Polarization "S" "P" "P" "P"Transmission (%) >99.75 >95 >90Polarization "P" "P"Incident angle (deg.) 0 0 0 0 56,4 56,4 10-30 45 45 45 0GDD (fs2) 100 100Testing service Spica LZH Spica LZH Spica Quantel Quantel OSU OSU Spica SpicaTest methodology Raster ISO Raster ISO ISO ISO Raster Raster Raster Raster Raster

"S" "P"

Participation and StatisticsAbsolute Coatings USA G&H, Ilminster UK Opturn Company Ltd. ChinaAdvanced Thin Films USA Hardin Optical Company USA Photonics Products Group USA Aerospace Times Laser China Infinite Optics USA Plymouth Gratings USA Agilent Technology USA Institute of Optics & Electr. China Precision Photonics Corp. USA Alpine Research Optics USA Jenoptik Laser Germany Quality Thin Films USA Altechna Co Ltd. Lithuania Jiutle China Research Electro-Optics USA Arrow Thin Films USA Kugler Germany RhySearch SwitzerlandBerliner Glas KGaA Germany LaCroix Precision Optics Sandia National Lab USA Carl Zeiss Germany Laser Components Germany Schott Switzerland Center for Physical S&T Lithuania LZH Germany Schott USAChangchuan Inst. of Optics China Laserhof Frielingen Germany SIOM China Colorado State University USA LaserOptik Germany Shichuan Dorder Technology China Corning USA LLNL USA SLS Optics UK Cutting Edge Coatings Germany Layertec Optical Coatings Germany Spectra-Physics USACVI Melles Griot UK Nikon Japan TelAztec USACVI Melles Griot USA Okamoto Optics Work Japan Tokai OpticalFiveNine Optics USA Optical Coatings Japan Tongji University ChinaFraunhofer Institute Germany Optida UAB Lithuania Twin Star Optics USA G&H, CCI USA Optimax Systems USA U of R, LLE USA G&H, General Optics USA PFG Precision Optics VLOC USA

Zygo USA

Participation by Companies

Participation and Statistics

Frequency of Participation

Participation and Statistics

Participation by Countries

61 participants from7 different countries

Statistics: Participants and Samples

total 308 samples

Statistics: Processes

Statistics: Materials

Statistics: Materials Total

Materials– exclusively SiO2 low index oxide– HfO2 predominantly used

as high index material

LIDT Measurement Methods Method ISO 21254– >10 sites per energy level– >100 sites per sample – 1 on 1, S on1 with conditioning– online damage detection (S on 1)– post inspection by Nomarski Microscope– evaluation of data set:

- 1 on 1: survival (damage probability) curve, 0%-LIDT - S on 1: characteristic damage curve, H∞

Nd:YAG-laser15ns; beamØ 250μm, TEM00Al-mirror, Ø25mm

0 100 200 300 400 500 600 7000,0

0,2

0,4

0,6

0,8

1,0

1/e2 = 1.44 mm

Dam

age

prob

abilit

y

Energy [mJ]1 10 100 1000

0

50

100

150

20050%-LIDT

H0 84,5 ± 5,1H1 171,7 ± 4,0Delta 0,56 ± 0,14

0%-LIDTH0 29,6 ± 11,7H1 134,9 ± 6,0Delta 0,91 ± 0,33

f = 50 mm, Deff = 17,6 um

ener

gy d

ensi

ty [J

/cm

²]

number of pulses

S on 1, Nd:YAG-laser= 50 ns, deff=17.6 μm

HR-mirror Ta2O5/SiO2

survival curve1 on 1, TEA-CO2-laser

= 100 ns peak, 4.5μs tailKBr-windows, 50pc, 500s

LIDT Measurement Methods Raster Scan Method– raster scan typ. 1 x 1 cm2, multiple times– typ. 90% intensity overlap– progressivley higher fluence per scan– increments depending on LIDT – online damage detection counting

damaged sites– visual post inspection– definition of damage:

- no damage: no visual change observed- initiation: 100 μm pinpoints observed, however no growth upon repeated illumination

- fail: pinpoints > 100 μm and growing with illumination, or more than 1% of total number of sites damaged

,

2019 1064-nm Mirror Thin Film Damage Competitioncomparison of raster scan and ISO 21254:

Experiment 2008: HR 1.064 nm, 0°, ns-regime, 35 samplesExperiment 2009: HR 780 nm, 0°, LIDT, fs-regime, 27 samplesExperiment 2010: AR 351 nm, 0°, LIDT, ns-regime, 29 samplesExperiment 2011: HR 193 nm, 0°, LIDT, ns-regime, 12 samplesExperiment 2012: PB 1.064 nm, 57°, ns-regime, p-pol., 26 samplesExperiment 2013: PB 1.064 nm, 57°, ns-regime, s-pol., 31 samplesExperiment 2014: BP 1.064 nm, n. 0°, ns-regime, 6 samplesExperiment 2015: BBHR ld 773 nm, 45°, ps-regime, 33 samplesExperiment 2016: BBHR ld 773 nm, 45°, fs-regime, 42 samplesExperiment 2017: HR 355 nm, 45°, p-pol, ns-regime, 35 samplesExperiment 2018: HR 1.064 nm, 0°, ns-regime, 33 samples

Review of Results

Overview on Processes (and Materials)– presentation of test results for each competition (excl. 2014, low number of samples) – best and second best LIDT per process, constant color code, all data J/cm2– summarising PIAD, APS, IAD, PAD to „IAD“– materials indicated in the graphs

HR 1064 nm, ns-regime

LIDT @ :1,064 nm, Ø:≈1mm, :≈5 ns, RS2008

almost all HfO2 /SiO2

HR 788 nm, fs-regime

LIDT @ :780 nm, Ø:≈180μm, :≈200 fs, ISO2009

ZrO2TiO2

HfO2

recent LIDT-value +>50%

AR 351 nm, ns-regime

LIDT @ :351 nm, Ø:≈580μm, :≈7.5 ns, RS2010

almost all HfO2 /SiO2

SiO2

HR 193 nm, ns-regime 2011

LIDT (H∞)

2011

almost all LaF3 /MgF2

+ Plasma

LIDT (H∞) @ :193 nm, Ø:≈330μm, :≈13 ns, ISO, S on 1

HR 193 nm, ns-regime

Pol.BS 1064 nm, s&p-pol, 56.4° AOI , ns-regime

LIDT @ :1,064 nm, Ø:≈530μm, :≈10 ns, ISO, S on 1

HfO2

Ta2O5

Al2O3Ta2O5

HfO2 HfO2 2012/2013

Pol.BS 1064 nm, s&p-pol, 56.4° AOI , ns-regime LIDT @ :1,064 nm, Ø:≈530μm, :≈10 ns, ISO, S on 1

2012/2013

BBHR 773 nm, p-pol, 45° AOI, fs-regime

LIDT @ :780 nm, Ø:≈0,09cm2, :≈40 fs, RS2015

HfO2 HfO2/Ta2O5

ZrO2

ZrO2

ZrO2/ Nb2O5

HfO2/ Nb2O5

HfO2

BBHR 773 nm, p-pol, 45° AOI, ps-regime

LIDT @ :780 nm, Ø:≈0,09cm2, :≈150 ps, RS

2016HfO2/Ta2O5

Ta2O5HfO2

ZrO2

Ta2O5

HfO2HfO2/SiO2

BBHR 773 nm, p-pol, 45° AOI, fs/ps-regime

fs:HfO2/Ta2O5

ZrO2

Ta2O5

HfO2HfO2/SiO2

ps/10

HfO2/ Nb2O5

HfO2

HfO2

ZrO2/ (Nb2O5)

HR 355 nm, p-pol, 45° AOI, ns-regime

LIDT @ : 355 nm, Ø:≈600 μm, :≈5 ns, RS2017

almost all HfO2 /SiO2

Al2O3

Al2O3

HR 1064 nm, ns-regime

2018

HfO2

Al2O3

HfO2

HfO2

Al2O3

LIDT @ :1,064 nm, Ø:≈1mm, :≈3 ns, RS

Comparison HR 1064 nm, ns-regime, 2008/2018

2008/2018

2018: LIDT @ :1,064 nm, Ø:≈1mm, :≈3 ns, RS2008: LIDT @ :1,064 nm, Ø:≈1mm, :≈5 ns, RS

Comparison HR 1064 nm, ns-regime, 2008/2018

2008/2018

2018: LIDT @ :1,064 nm, Ø:≈1mm, :≈3 ns, RS2008: LIDT @ :1,064 nm, Ø:≈1mm, :≈5 ns, RS (factor 1.29)

2018: LIDT @ :1,064 nm, Ø:≈1mm, :≈3 ns, RS scaled (factor 1.29) 2008: LIDT @ :1,064 nm, Ø:≈1mm, :≈5 ns, RS

10 ns

100 ps

10 ps

1 ps

100 fs

10 fs

1 ns

e-beam / IAD

sol gel

sputtering

boat

e-beam

HfO2

HfO2

HfO2

HfO2 / Nb2O5

Al2O3

SiO2MgF2 / AlF3/ LaF3 ns

ps

fs

General Trends: Overview Best Performance

10 ns

100 ps

10 ps

1 ps

100 fs

10 fs

1 nsHfO2

HfO2

HfO2

HfO2 / Nb2O5

Al2O3

SiO2MgF2 / AlF3/ LaF3 ns

ps

fs

General Trends: Materials

HfO2

HfO2

HfO2

HfO2 / Nb2O5

HfO2Al2O3SiO2

MgF2 / AlF3/ LaF3

high EG

10 ns

100 ps

10 ps

1 ps

100 fs

10 fs

1 nsHfO2

HfO2

HfO2

HfO2 / Nb2O5

Al2O3

SiO2MgF2 / AlF3/ LaF3

General Trends: Packing Density

HfO2

HfO2

HfO2 / Nb2O5

high ρP

HfO2Al2O3

SiO2MgF2 / AlF3/ LaF3

lower ρP?

General Trends: Wavelength

LIDT vs. wavelength– scaled to 7.5 ns– all LIDT data– neglecting different

damage mechanisms forpulse duration regimesand testing methods

LIDT vs. wavelength– total average all data per λ– scaling in literature:

often: x = 1 or 2

SummaryOrganisation and Procedure– one decade of Boulder Damage Competitions with 8 different sample types– 308 samples tested sent in by 61 different participents from 7 countries– ISO and RS tests performed in fs-ns regime from the DUV to NIR

→ BDS Competition will be continued…

Trends:– best achieved threshold values increase with wavelength– with the exception of fluorides at 193 nm, SiO2 exclusively applied as low index material– HfO2 /SiO2 dominant material combination in the NIR (exception: HR 355nm)– wide band gap materials offer advantages in the UV/DUV – porous coatings structures (thermal processes) perform better in the ns-regime – higher packing density coatings (sputtering) are good choises for shorter pulses (ps-fs)

Details:– sputter processes (IBS) are improving over the last years– no correlation between s and p best performance for polarisers observed– best processes and samples differ for the fs- and ps-regime – recent HR 1.064nm test revealed lower values than first BDS competition 2008

2019Raluca A. Negres, Christopher J. Stolz, Lawrence Livermore National Lab. (USA)

A double-blind laser damage competition will be held…The results will be shared at SPIE Laser Damage 2019. The mirrors must meet the following requirements (substrate 50 mm (+/- 1 mm) in diameter and at least 10 mm thick ):• Reflectance >99.5%• Wavelength 1064 nm• 0 degrees incidence angle• Pulse length 5-ns; Single-longitudinal mode laser; Repetition rate 10 Hz• Environment: Ambient air (normal and low humidity possible)• No wavefront or stress requirement• No surface quality requirement.This is a continuation of last year’s laser damage competition aiming to assess the correlation in damage resistance of these 1064-nm HR coatings as inferred from two different damage testing protocols, i.e. raster scanning (2018) vs. ISO testing (2019). Any new sample submittals must be preapproved by Raluca Negres at (negres2@llnl.gov). Raluca Negres, L-470, Lawrence Livermore National Lab., 7000 East Avenue, Livermore, CA 94550

See LD Conference Call on SPIE-website for full details….

1064-nm Mirror Thin Film Damage Competition

Thank You

for your attention