Anti-reflective, high-reflective, beamsplitter, filter, patterned, conductive, metallic, and high-laser-damage-threshold coatings from UV through infrared.
IRD operates electron-beam and DC magnetron sputtering chambers in-house, which keeps the coating conversation attached to substrate, surface quality, wavelength, angle of incidence, and end-use environment. Send the requirement and the technical team reviews it before quoting — free of charge on a new design.
Start with what the optic must transmit, reflect, block, conduct, survive, or reference.
The stack follows from what the optic has to do, the substrate under it, and the angle it actually sees — in that order.
Single-layer MgF2 through high-efficiency multilayer AR, BBAR, and V-coat designs, matched to substrate and wavelength so more of the light reaches the far side of the optic.
Protected and enhanced aluminium, silver, gold, and dielectric stacks, ultra-high-reflective mirror coatings, and high-laser-damage-threshold AR and mirror designs.
HLDT capability exceeds 80 J/cm² at 1064 nm, 1 ms
Dichroic, fluorescence, narrow-bandpass, multi-bandpass, edge, and notch filters, with polarizing and non-polarizing beamsplitter stacks developed around wavelength, angle, and system balance.
Chrome, precious metal, and aluminium patterns for masks, gauges, and datums, plus metallization and ITO conductive layers where the optic is also an electrode or a reference.
IRD's own high-damage-threshold research is explicit that damage threshold is largely determined before any layer is deposited. These are the controls that decide whether a coating run succeeds.
Substrate composition and homogeneity, surface finish, subsurface damage, residual stress, polishing and cleaning residue, dust and other contamination, and the coating-substrate pair all contribute to damage threshold. Fabrication runs staged fixed-abrasive grinding and loose-abrasive lapping so each step removes the micro-cracks left by the one before it.
Polishing target for high-damage-threshold optics: better than 10 Å rmsHand cleaning with isopropyl alcohol, cascaded detergent baths, deionised-water rinsing, oven baking, spin drying, proprietary solvent washing, and hydrofluoric acid etching for stress relief. Most high-damage-threshold optics get a cleaning process built for the part rather than a general optics clean.
On one high-power mirror program, sharp slot edges shed fibres during cleaning and those fibres became coating defects that pulled the damage threshold down. A 50 µm bevel — the maximum the clear aperture allowed — plus a cleaning process built around it solved it. That decision belongs at design review, not after polishing.
Electron-beam evaporation and DC magnetron sputtering are different tools with different strengths. IRD's coating engineers select the method against the design and substrate, and run single- and multi-layer metallic, broadband, V-coat, polarizing, and HLDT stacks across both.
Coating feasibility is defined by the complete optical requirement. Provide substrate, clear aperture, spectral target, angle, polarization, environment, and inspection method.
| Attribute | Typical | Best case | Application note |
|---|---|---|---|
| Deposition | Electron beam | DC sputtering available | Method selected by design and substrate |
| Laser damage threshold | Application-defined | >80 J/cm² at 1064 nm, 1 ms | HLDT stacks on laser-quality substrates |
| Spectral coverage | Visible | UV through IR | Application-specific stack design |
| Layer structure | Single layer | Complex multilayer | AR, HR, beamsplitter, and filter stacks |
| Patterning | Full aperture | Custom pattern | Chrome, metals, masks, and datums |
These are IRD's published capability figures, not a guarantee for a given stack. Reflectivity, transmission, and damage threshold all depend on wavelength, polarization, angle of incidence, and the substrate beneath the coating, and IRD's published values do not state those conditions — send your operating conditions and the team will confirm against them. IRD does not publish in-house laser-induced damage testing, so treat the 80 J/cm² figure as a reported process capability rather than a certified per-lot result.
When fabrication and coating are reviewed together, edge handling, masking, cleaning, fixture contact, witness samples, and inspection can be designed into the process instead of resolved after polishing. That is the practical argument for coating at the same supplier that made the substrate.
The IRD AdvantageUse these lists to frame the first review. The drawing, environment, performance requirement, inspection method, and volume determine the final route.
A web page is hard to attach to a review packet. These are IRD's own published technical documents on the questions this page raises.
IRD's account of what actually moves damage threshold — substrate composition and homogeneity, subsurface damage, residual stress, polishing and cleaning residue, contamination, and the coating-substrate pair — plus the slotted-mirror bevel case study in full.
PDFTechnical articleA working tour of AR, high-reflective, dielectric, and metallic coatings, the deposition methods behind them, and how layer materials and thicknesses are chosen against a substrate's refractive index.
ArticleTechnical articleHow long-pass, short-pass, bandpass, notch, and dichroic filters differ, and when filter glass, a thin-film coating, or a combination of both is the right route.
ArticleThe finished component often crosses product categories. These pages cover the nearest materials, processes, and program contexts.
Send the substrate and its surface specification, the clear aperture, the spectral target with tolerances, angle of incidence, polarization, damage-threshold requirement with its wavelength and pulse conditions, operating environment, annual volume, and the acceptance data and test method you need with the parts. For a new design, the technical team runs a no-cost Design for Manufacturability review before quoting.
Or call 320.693.7217. If IRD is coating your substrates rather than its own, send the incoming surface specification too — it usually sets the ceiling on what the stack can do.