HIGH AND LOW REFRACTIVE INDEX COATINGS FOR OPTICS

OPTICS FOR ALL-WEBINAR (APRIL 14, 2021)

HIGH AND LOW REFRACTIVE INDEX COATINGS FOR OPTICS

Jukka Perento, Inkron Oy

CONFIDENTIAL

TOPICS

Introduction

Portfolio for Optics

Nano-imprint lithography

Application and device level examples

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INKRON, SPECIALIST IN SILOXANE CHEMISTRY

INKRON – A NAGASE GROUP COMPANY

• R&D and manufacturing in Espoo, Finland. Opto-packaging team in Taiwan.

NAGASE AND NAGASE CHEMTEX

• Headquartered in Tokyo Japan. Related business manufacturing in Harima, Japan; Wuxi, China; and Ohio, USA.

• 7,200+ employees, global operations and annual turnover ca. US$8bn.

Japan

Taiwan

Finland

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LED PACKAGING

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• Die attach adhesives

• LED encapsulants

OPTICAL DEVICES

• Light management coatings

• Nano-imprint lithography, DOE

• High and low refractive index

TYPICAL MARKETS

PRINTED ELECTRONICS

• Printable inks

• Screen print, inkjet

• Structural adhesives

MATERIALS FOR OPTICS

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HIGH RI NIL COATINGS

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• RI range 1.55-1.9x

• Optically clear

• NIL processable

• Matching adhesion promoter

EDGE BLACKENING

• High RI (range 1.55-1.9x)

• High Optical density (OD)

• RI matched with the substrate

• Even 96 % reduction of backscatter (compared with “standard” black)

ESSENTIAL SOLUTIONS FOR AR, DOE AND OPTICS

LOW RI COATINGS

• Low RI, range 1.1-1.4

• Antireflection VIS/IR

• Gap filling, cladding layer

• Optically clear

IN SEARCH OF RIGHT REFRACTIVE INDEX COATING

n = 1.5 – 1.9x

Optical Coatings and NIL

n = 1.4 - 1.7

Optical Bonding

n = 1.1 - 1.4

Optical Coatings and Gap Fill

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HIGH RI NIL COATINGS’ OPTICAL PERFORMANCE

IOC n = 1.7 on glass*

IOC n = 1.8 on glass*

IOC n = 1.9 on glass*

IOC n = 1.8 on subst. corrected film transmission

IOC n = 1.9; Abbe = 17

IOC n = 1.8; Abbe = 19

IOC n = 1.7; Abbe = 36

*) Each measurement done with n matching Schott

RealView glass substrate

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CONFIDENTIAL 9

INKRON’S NIL FACILITY

NIL COATINGS’ IMPRINT PERFORMANCE

*Slanted grating master manufactured and provided by NIL Technology AsP.

• IOC with n = 1.7 – 1.92 shows great pattern fidelity in various stamp shapes and aspect ratios • Line/space gratings with linewidths down to 75nm with aspect ratio >3.5; Bi-directional 30° slanted

gratings with 400nm vertical height; Various pillar patterns (also non-spherical).

~ 50 nm residual layer

IOC 172 (n = 1.7) IOC 132 (n = 1.8) IOC 133 (n = 1.9)

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OPTICAL BLACK MATERIAL

1. Minimize the reflection at the edge of the glass by refractive index matching between the glass and optical black material.

2. Minimize light re-entering from the optical black coating to the high RI glass by having high absorbance black optical coating (high optical density, OD).

3. Minimized re-entering due to the scattering.

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OPTICAL BLACK AT LENS EDGE

96% decrease in reflectance when RI of the IOB coating is matched with the

glass wafer (n=1.9)

• Edge reflectance (%) drops from 10% to 1% with optical black coating • … and 96% (from 1% to 0.04%) with black coating n-value optimization• OD up to 5 with 25 um film thickness

Light reflectance on (n = 1.9) glass lens edge without and compared with different Inkron’s index of refraction optically black

coatings

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• Lens wafer to cover-lens stacking

LENS & HIGH/LOW-N STACKING

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Glass

GlassIAP-110 primer

IOC-133 RI 1.9

IBA-210 RI 1.4

Δn = 0.5 @589nm

Alternating:IOC n=2.05; 30nmIOC n=1.25; 130nm

• High – low refractive index layer stacking

Δn = 0.8 @589nm

GAP FILLING

APPLICATION EXAMPLES OF LOW RI COATINGS

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ANTIREFLECTION COATINGS

CLADDING LAYERS

• Particle free low RI, No haze or scatter

• Antireflection in VIS/IR

• Light guide optimization REFLECTED

PASSED

CLADDING

LIGHT- GUIDE

NO CLADDING

AR coating in visible area

AR coating in IR area

DEVICE LEVEL EXAMPLES

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3D SENSOR: TIME-OF-FLIGHT SENSOR

APPLICATION EXAMPLES

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• Sends a photon to the object, measures the return time of reflected light -> 3D depth map of the object

3D SENSOR: STRUCTURED LIGHT SENSOR

• Illuminates a known pattern on an object

• Pattern deformation used to calculate distance

AR GLASSES

• Waveguide (diffractive optics) for AR/XR glasses

DISPELIX AR GLASS DEMO

3D SENSORS

OTHER APPLICATIONS OF (DIFFRACTIVE) OPTICS

WWW.INKRON.COM

THANK YOU

info@inkron.com

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