Flat Windows for Precision Laser Applications

PP-UVFS-25.4-6.35-2AR40 UVFS Laser Window 25.4mm

PP-UVFS-25.4-6.35-2AR40 UVFS Laser Window 25.4mm

$121.00
Sold by: Optoman Ships from: Lithuania
Specifications
Substrate Material: UV Grade Fused Silica (UVFS))
Design Wavelength 1: 532 nm
Diameter (or Largest Dimension): 25.4 mm
Thickness: 6.35 mm
Clear Aperture (CA): 22.86 %
Sapphire Optical Flat Windows

Sapphire Optical Flat Windows

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Sold by: CSOC Ships from: China
Specifications
Substrate Material: N-BK7, Fused Silica, UV Grade Fused Silica (UVFS)), IR Grade Fused Silica (IRFS), Sapphire
Diameter (or Largest Dimension): 200 mm
Thickness: Not Specified
Antireflection Coating: Coated, Uncoated
Surface Quality (Scratch-Dig): 10-5, 20-10, 40-20, 60-40
Optical Grade CaF2 Calcium Fluoride Window

Optical Grade CaF2 Calcium Fluoride Window

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Sold by: Henan UM Optics Ltd Ships from: China
Specifications
Substrate Material: CaF2, IR Grade CaF2
Diameter (or Largest Dimension): 25 mm
Thickness: 2 mm
Surface Quality (Scratch-Dig): 60-40
Surface Flatness: <= Lambda/10, <= Lambda/20, <= Lambda/8, <= Lambda/6, <= Lambda/4, <= Lambda/2, <= Lambda, <= Lambda/40

Did You Know?

An optical flat by definition is a polished flat surface that can be used as a reference against which the flatness of an unknown surface may be compared by measurement. An optical flat utilizes the property of interference to exhibit the flatness on a desired surface. Optical flats are versatile optical components used in many applications, such as inspection of gauge blocks for wear and accuracy, as well as the testing of various components including windows, prisms, filters, mirrors, etc. Optical flats are sometimes given an optical coating and used as precision mirrors for special purposes, such as in a Fabry–Pérot interferometer or laser cavity.

Related Resources

Frequently Asked Questions

Flat windows are plane-parallel optical substrates designed to transmit light while providing environmental isolation, pressure containment, or protection for internal optics. Unlike lenses, they have no optical power (no intentional curvature), so they ideally do not focus or diverge the beam and mainly introduce only transmission loss, reflection, and potential wavefront distortion if not properly specified.

Flat Windows for Controlled Light Transport

Flat Windows are plane-parallel optical plates used to transmit, protect, or sample laser and broadband light beams without altering their wavefront. In laser and photonics setups, these components serve as protective barriers for sealed cavities, vacuum chambers, diagnostics ports, and high-power beam paths while maintaining defined optical performance.

On FindLight, Flat Windows span a wide range of optical materials, including UV-grade fused silica, BK7 and other crown glasses, sapphire, CaF2, MgF2, ZnSe, and specialty infrared crystals. Options include uncoated substrates for broadband use or single-/multi-layer AR coatings optimized for UV, visible, NIR, or MIR laser lines.

Typical Specifications for Flat Windows

  • Dimensions: Standard diameters from a few millimeters to 100 mm+, and rectangular apertures for beamlines and viewports.
  • Thickness: From sub-millimeter plates to several millimeters for mechanical strength or pressure/vacuum interfaces.
  • Surface quality: Commonly 20-10 to 60-40 scratch-dig, depending on imaging or high-power requirements.
  • Flatness and parallelism: λ/10 to λ/2 at specified wavelengths, with tight wedge tolerance to minimize beam deviation.
  • Coatings: Single- or broadband AR coatings, high-damage-threshold designs for pulsed lasers, and protective or DLC coatings for harsh environments.
  • Resistance: Temperature range, chemical durability, and laser damage threshold suited to CW or pulsed operation.

Use Cases and Selection Guidance

Flat Windows are deployed in laser machining heads, measurement cells, vacuum and pressure viewports, spectroscopy setups, and protective front optics for scanner systems. For high-power lasers, prioritize substrate thermal conductivity, surface quality, and coating damage threshold. For imaging or metrology, prioritize flatness, surface quality, and low transmitted wavefront error.

When comparing Flat Windows on FindLight, evaluate material transmission at your operating wavelength, AR coating bandwidth, clear aperture, and mechanical tolerances. Review datasheets for flatness, parallelism, and environmental ratings, then request quotes directly from multiple suppliers to compare pricing and lead times. No registration is required to submit RFQs, enabling rapid sourcing of Flat Windows that match your laser system and light transport requirements.