Iridian’s capabilities include the ability to design and manufacture complex “specialty optics” including multi-zone filter (MZF) arrays and prism beam-splitter/combiner assemblies.

Multi-Zone Filter Arrays (MZF)

The ability to offer spatially varying spectral performance on a single substrate can have many advantages for optical designers. Iridian offers both assembled multi-zone filter arrays and patterned multi-zone optical filters (sometimes referred to as multi-spectral filters (MSF)) to address these growing needs. Features of Iridian’s MZF offerings include:

Filter types:

• Long-pass or short-pass filters (LPFs/SPFs)
• Bandpass filters (BPFs)
• Notch filters
• Black absorbing coatings
• Anti-reflection coatings (ARs)
• High-reflectors (HR)

Wavelength range:

• UV (300nm) to the long-wave infrared (LWIR 15 um)
• Customization for size, spectral performance, and lay-out (number and size of zones)
• “Butcher-block” assembled arrays
• Monolithic patterned arrays
• Hybrid approaches combining both assembly and patterning

Iridian’s multi-zone filter butcher-block assemblies address needs in multi-spectral imaging applications requiring many bands, complex filter coatings or with constraints on cost. In this process coatings are deposited on separate substrates that are then attached together using robust assembly methods.

Butcher-block MZF assemblies offer:

• Zone-to- zone transitions of < 250 μm
• No limit on number of bands
  • No limit on single band spectral complexity (whatever can be made as a standalone filter can be made into an assembled array)
• Individual band widths as narrow as 0.75 mm
• Masked black coatings can be added to reduce stray light and to define bands

For applications requiring a small transition zone or patterns not possible to achieve by assembly, Iridian’s monolithic patterned multi-zone filters are the perfect choice. Iridian’s in-house photolithography lab is housed in a Class 1000/ISO Class 6 clean room capable of patterning up to 150 mm diameter wafers. Multi-step patterning can be performed creating MZF’s with:

• As many as five different zones
• Zone-to-zone transitions of 5-100 μm
• Perfect co-planarity (monolithic)
• Any band shape can be patterned (can be 1D or 2D arrays)

Prism Beam-Splitters

When a plate filter approach won’t meet build constraints for alignment or mounting Iridian builds custom optically contacted prism beam-splitters/combiners with wavelength selective dichroic filtering effectively embedded in glass.