Dual Wavelength AR coat spectrum
measured using Cary 500 Spectrophotometer
(referenced to glass)
transmission (%) vs wavelength (nm)

Ionfab 300 Plus
( Optofab configuration )

accurate thickness control by X tal monitor or optical monitor
and time by very short reliable source shut start and shutt off

low absorption by very low impurity levels
chamber design based on 20 years of experience for optical coatings

very smooth surfaces, very little scattering

Ion Beam Deposition
filamentless RF source
filamentless assist RF source
filamentless PBNs

Deposition of Dual Wavelength AR coating
using White Light Optical Monitor (WLOM) calibration

8 layer AR Coat

Layer materials: Ta2O5, SiO2

Deposition rates
>12.5 nm/min (SiO2)
>14.5 nm/min (Ta2O5)

Uniformity
<± 0.5 % over 75mm thick annulus
<± 0.2 % over 10mm thick annulus
centred at 75mm substrate radius

Substrate 1” dia fused silica held in 8” carrier plate

AR Performance: Transmission
99.815 % @ 532nm
99.390 % @1064nm

Time endpoint for all layers System
calibrated using QW deposition by WLOM

typical ion beam layout

Optofab 3000
= Ionfab 300 Plus modified to achieve very high rates
at excellent uniformities over small substrates

excellent thickness control via:

1) two independent cooled quartz crystal monitors

2) in-situ optical monitor (laser or white light versions)
with patented optics bracket (low noise, maintenance free)
to allow monitoring at any process angle with no re-alignment

3) deposition by time: optimised very fast source shut down
to ensure accurate, repeatable coating terminations

Low impurity levels ~50ppm

Exceptional Absorption

Source designed to retain contamination

Low maintenance self aligning grids ensure
fully focussed beam and low contamination

Focussed beam onto target ensures
low divergence and impurities

Plasma Assist Source aperture to ensure stoichiometry