• broadband-dielectric-mirror

Broadband Optical Mirrors with Dielectric Coatings

Mirrors are an important part of optical applications. They are commonly used to fold or compact an optical system. Standard and precision flat mirrors feature metallic coatings and are good all-purpose mirrors that come in a variety of substrates, sizes and surface accuracies. They are a great choice for research applications and OEM integration. Laser mirrors are optimized to specific wavelengths and use dielectric coatings on precision substrates. Laser mirrors feature maximized reflection at the design wavelength as well as high damage thresholds. Focusing mirrors and a wide variety of specialty mirrors are available for customized solutions.

Paralight Optics’ optical mirrors are available for use with light in the UV, VIS, and IR spectral regions. Optical mirrors with a metallic coating have high reflectivity over the widest spectral region, whereas mirrors with a broadband dielectric coating have a narrower spectral range of operation; the average reflectivity throughout the specified region is greater than 99%. High performance hot, cold, backside polished, ultrafast (low delay mirror), flat, D-shaped, elliptical, off-axis parabolic, PCV cylindrical, PCV Spherical, right angle, crystalline, and laser line dielectric-coated optical mirrors are available for more specialized applications.

Paralight Optics offers broadband dielectric mirrors with excellent reflectance over multiple spectral ranges. For detailed information on coatings, please check the following Graph of Reflectance curve at 45° AOL for Broadband Dielectric HR Coatings optimized for the range of 350 – 400nm, 400 – 750 nm, 750 – 1100 nm, 1280 – 1600 nm for your references.



Material Compliant:

RoHS Compliant

Round Mirror or Square Mirror:

Custom-made dimensions

High Reflectivity:

Ravg > 99.5% for AOI (Angles of Incidence) from 0 to 45°

Optical Performance:

Excellent Reflectance over Specified Wide Range


Common Specifications:


Note: these mirrors are not suitable for ultrafast applications.


Ranges & Tolerances

  • Substrate Material

    Fused Silica or Custom-made

  • Type

    Broadband Dielectric Mirror

  • Size


  • Size Tolerance


  • Thickness


  • Thickness Tolerance

    +/-0.2 mm

  • Chamfer

    Protective < 0.5mm x 45°

  • Parallelism

    ≤3 arcmin

  • Surface Quality (scratch-dig)


  • Surface Flatness @ 632.8 nm

    < λ/10

  • Clear Aperture

    >85% of Diameter (Round) / >90% of Dimension (Square)

  • Coatings

    Dielectric HR coating on one surface, Ravg >99.5% for unpolarized rays, AOI 0-45deg, finely ground or inspection polished on the backside surface



These plots of the reflectance show that each sample of our four dielectric coatings for the different spectral ranges is highly reflective. Due to variations in each run, this recommended spectral range is narrower than the actual range over which the optic will be highly reflective.
For applications that would benefit from having a small portion of the beam transmitted through the optic, consider one of our backside polished mirrors. Alternatively, if you need a mirror that bridges the spectral range between two different coatings, consider a metallic mirror.


Reflectance Curve for Broadband Dielectric HR Coated (400 - 750 nm, unpol.) Mirror at 0° AOI


Reflectance Curve for Broadband Dielectric HR Coated (750 - 1100 nm, unpol.) Mirror at 0° AOI


Reflectance Curve for Broadband Dielectric HR Coated (1280 - 1600 nm, unpol.) Mirror at 0° AOI