Silicon Reflective Longpass Filter, Ø12.5 mm, 1050 nm, OD 3.0

Overview

Longpass filters provide a sharp cut-on at a specific wavelength. Widely used for order sorting, they isolate broad spectral regions while transmitting the desired energy and blocking unwanted light. Built on an IR-transmitting optical substrate coated with a hard, durable outer-surface dielectric film, they withstand routine cleaning and suit any high-quality optical assembly — making them especially well suited to FTIR spectroscopy and thermal imaging. Coatings are available on silicon or germanium substrates.

Applications

• FTIR spectroscopy
• Thermal imaging
• Order sorting & spectral-region isolation
• Mid-IR & laser systems

Construction & Performance

• Substrate: Silicon
• Coating: Dielectric Coating (reflective longpass)
• Dimensions: Ø12.5 mm
• Thickness: 1.0 mm
• Start wavelength: 1050 nm
• OD: 3.0
• Transmission: >85%
• Blocking range: 200–1050 nm
• Passband: 1100–2100 nm
• Coating spec: HR@200-1050 nm, T>85%@1150 nm
• Clear aperture: 90%
• Parallelism: <10 arcmin
• Surface quality: 80-50
• Surface flatness: 3–5 λ @ 633 nm

Storage & Handling

For optimal performance, store and use at 25 °C and 40–60% relative humidity. If the surface becomes contaminated, clean gently with ≥99% alcohol and lint-free lens tissue; never use coarse cloth, water, or abrasive cleaners, which may damage the coating.