Integrating Spheres

Integrating spheres generally function as a light collector. The collected light can be used as a diffuse illumination source or as a measurement source.

In the Avantes line of integrated spheres, the spheres are mostly used as measurement source. The basic principle of operation is that light enters the integrating sphere through the sample port, goes through multiple reflections and is scattered uniformly around the interior of the sphere. The detection fibre optics are SMA coupled to the port at the side of the sphere which is viewing illumination on a baffle, independent of the angular properties of the light at the sample port. The baffle prevents first reflections from entering the detection fibre.

The AvaSphere integrating sphere family can be delivered with an active diameter of 30, 50 or 80mm and an SMA port at 90 degrees for irradiance and reflection measurements.

The reflection sphere has an additional SMA connector port at 8 degrees, for direct illumination, coupling the light into sphere through a fibre and a COL-UV/VIS collimating lens connected to a light source.

The AvaSphere-30 has a sample port diameter of 6mm, the AvaSphere-50, a 10mm sample port and 15mm for the 80mm diameter sphere.

All sample ports are knife-edge thus ensuring 180 degree field of view of the sample port.

The irradiance version of the integrating sphere can be used to measure light sources (Laser, LED, and Halogen Lamps). For the irradiance measurements of LED's, a special adapter was developed to be connected to the AvaSphere-50-IRRAD. The adapter can hold 3, 5 and 8mm LED's in the correct and reproducible position inside the sphere. 

The reflection version is used to measure total integrated reflectance of a surface, as well as for colour measurement and fluorescence spectroscopy. The measurement principle is based on direct illumination and indirect reflection. A light source may be connected to the 8 degree SMA connector port through a fibre optic bundle to make the integrating sphere an ideal uniform light source. The inside of the integrating sphere is made out of highly reflective diffuse material that gives a light diffuse reflection (>96 %) over a wide wavelength range (250-2500 nm). A special gloss-trap is available for the AvaSphere-50-REFL reflection sphere to exclude specular reflection in the measurement. This option needs to be ordered together with the sphere. In case specular reflection needs to be included, a white reflective part can be mounted in the position of the gloss trap.

Technical Drawing, Reflection Integrating Sphere

Technical Drawing, Irradiance Integrating Sphere

Integrating Sphere Reflection Curve

LED Measurement

Technical Details

Ordering Information