Spectralon® Reflectance Material

 

Labsphere Spectralon Diffuse Reflectance Material 

The Highest Diffuse Reflectance of Any Material or Coating from 250-2500nm

Spectralon is Labsphere's patented and award-winning diffuse reflectance material. Its is a solid, thermoplastic based upon PTFE that exhibits the highest diffuse reflectance of any material or coating, up to 95% from 250-2500nm, and 99% from 400-1500nm. Spectralon is manufactured in optical, laser and space grades and is widely used in applications as diverse as integrating spheres, laser cavity pumping chambers, reflectance targets, lamp reflectors, display backpanels, line scanners and digital imaging devices. A wide variery of optical reference materials are made from Spectralon, including standards of reflectance and BRDF (scatter). Spectralon can be doped with various materials to create standards of grey scale reflectance, fluorescence, wavelength and colour.

Spectralon is not a coating, rather it is a solid material that is machined into reflectors. It is a bulk rather than a surface reflector, with the highest reflectance achieved at thicknesses of ≥7mm. In thinner section, the reflectance of Spectralon decreases (for example, dropping from 99.0% to 93.3% at 1mm thickness @ 555nm). For further information on the relationship between thickness and reflectance, download our Tech Guide to Coatings & Materials from the Knowledge Base box opposite.

Unlike most other diffuse reflectance coatings for the UV-VIS-NIR band, Spectralon exhibits an extreme environmental stability. It is hydrophobic,  thermally stable to 350°C, UV-resistant* and chemically inert to all but the most powerful bases such as sodium amide and organo-sodium or lithium compounds. The material is durable and maintains its reflectance even under harsh laboratory or field conditions. Spectralon can easily cleaned by washing; for badly soiled reflectors, light sanding can restore the original reflectance.

* A useful reference is the NPL paper entitled "Ageing of Materials Under Intense UV Radiation" by Gibbs, D R, Duncan, F J, Lambe, R P, Goodman, T M published in Metrologia, 1996, 32, (6), 601-607. Click here for a link to the publications area on the NPL web site.

Property ASTM Test Value
Wavelength Range    250-2500nm 
Reflectance    >95%
>99% 400-1500nm 
Laser Damage    >4J/cm2
(1064nm, 20ns)
Density    1.25-1.5g/cm3 
Water Permeability  D-570 <0.001% (hydrophobic) 
Hardness  D-785  20-30 Shore D 
Thermal Stability    Decomposes
>400°C 
Coefficient of Linear Expansion  D-696  5.5-6.5 x 104
in/in - °C 
Vacuum Stability    No out-gassing 
Flammibility    Non-flammable
(UL rating V-0) 
Yield Stress  D-638  208psi 
Refractive Index  D-542  1.35 

Optical Grade Spectralon, SRM-99O

Optical grade Spectralon forms the basis of our integrating spheres as well as our diffuse reflectance standards and targets. Optical grade material can be machined into integrating spheres with diameters up to 300mm, while larger spheres can be made using tiles of Spectralon. Products made using Spectralon deliver marked performance gains compared with ordinary diffuse reflectance coatings. Spectralon is non-wavelength selective, with a variation in reflectance of just 0.5% between 360 and 740nm. Please note that Spectralon is not suitable for use at wavelengths longer than 2.5µm due to strong absorption at 2.8µm and between 5.4 and 8µm.

Laser Grade Spectralon, SRM-99L

Laser Grade Spectralon is the perfect choice of material for use as a pump chamber reflector in diode and lamp pumped solid state lasers and lamp pumped dye lasers. Spectralon exhibits diffuse, high reflectance at the pump wavelengths of these lasers leading to increased slope efficiencies, higher energies, increased gain uniformity, improved beam quality and reduced risk of parasitic oscillations. Spectralon is thermally stable, hydrophobic and easily machined into bespoke reflectors.

Space Grade Spectralon, SRM-99S

Space Grade Spectralon has gained widespread acceptance as a reflectance target material used on satellites for earth-observing remote sensing applications. This form of Spectralon is characterised by an extremely high cleanliness and low levels of outgassing whilst retaining Lambertian high reflectance. The material is procesed in a clean-room environment and packaged to protect against molecular and particulate contamination. Space-grade Spectralon has undergone extensive testing for VUV exposure, Proton bombardment, atomic oxygen exposure, alpha-Lyman radiation, outgassing and static charge testing by national laboratories, such as Jet Propulsion Laboratory, NASA Goddard Space Flight Center, TRW and CSEM. This testing has led to the development of a stringent manufacturing process that eliminates potential contaminants which lead to UV degradation.

Ordering Information

Spectralon is not supplied as a bulk material. Instead, reflectors are machined according to a customer-supplied drawing. Our dedicated Spectralon machine shop and expert machinists familiar with the nuances of working with this material ensure that your reflectors are of the highest quality and performance. We operate a fast-track process to help us to respond quickly to one-off or prototype projects. We are just as happy supplying one or one hundred reflectors - there is no minimum order quantity.

» Submit an enquiry for machined Spectralon reflectors

 

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Further Information

» Laser Grade Spectralon

» Optical Grade Spectralon

» Space Grade Spectralon

 



Knowledge Base

» Spectralon Care

» Spectralon Design Guidelines

» Spectralon Material Safety Datasheet

» Technical Guide: Diffuse Reflectance Coatings & Materials

Related Products

» 6080 Coating

» Laser Cavity Reflectors

» Reflector Fabrication

» Spectralon Standards

» Spectralon Targets