Integrating Spheres Overview
Integrating spheres are a highly useful if often misunderstood optical device. The purpose of an integrating sphere is to spatially integrate radiant flux, either from an external or an internal source of radiation. The efficiency of an integrating sphere is determined by a number of factors, including the size and number of ports, the size and location of baffles or screens, the number of inclusions in the sphere, and most importantly, the reflectance and diffuse nature of the sphere coating.
Depending on port position, baffling, and to an extent, sphere size, integrating spheres can be configured for a number of applications, including:
- Light collection from internal or external source (lamp measurement photometry)
- Laser power measurements
- LED spectral and SPD measurements
- Reflectance of either specular or scattering samples
- Total or diffuse only transmittance measurements
- Cosine receptors
- Uniform light sources
An excellent overview of the use and theory of integrating spheres
can found in the CORM (www.corm.org)
publication "Bibliography of Flux Integrating Devices for Radiometric
and Photometric Applications". Other useful links for photometry,
Radiometry, and measurements using integrating spheres include
Jim Palmer's FAQ .
and the
NIST Websites on radiometry and photometry.
Avian Technologies offers a number of standard integrating spheres that are configured for particular applications such as collection of light (cosine collectors, lamp and laser power measurement) or reflectance/ transmittance measurements. These pre-configured spheres offer an economical entry into the field of integrating spheres and are configured to allow the user to perform multiple functions with a single system. We also offer accessories such as laser targets, light traps, reflectance and transmittance standards to fully optimize your sphere system.
Avian Technologies also offers two sphere systems configured for particular applications. One offers the ability to perform reflectance or total transmittance measurements at variable incident angle to the sample, which is mounted in the center of the sphere. The second system allows the measurement of total transmittance and diffuse-only transmittance of scattering colloidal solutions/suspension that are typical of biological applications.
For technical support on sphere systems or for pricing of systems, please call or email us.
Integrating Spheres
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