4" Integrating Sphere (1" and .5" port plugs sold seperately)

• Integrating sphere with classical exterior or cubical exterior • Machined port plugs match interior sphere curvature • Post mount or slit flat (for cubical model)

  An integrating sphere is a hollow sphere coated internally with a matte finish, diffusing type material. The sphere is provided with ports or openings for an incoming beam of light, a sample specimen and a detector. Integrating spheres typically function as a light collection device. The collected light can then be used as a diffuse source or as a measurement device.

  Integrating spheres operate by allowing light to enter the sphere through a sample port, then through multiple reflection is scattered uniformly around the interior of the sphere by the diffuse internal sphere coating. The diffused light is then detected at a port configured with a detector device.

  Integrating sphere efficiency is determined mainly by the physical size of the sphere, the number of ports and most importantly the diffuse nature and reflectivity of the internal sphere coating. 

Sphere considerations:
  Selection of the appropriate integrating sphere for your application typically can be determined by the following important factors:

  • Internal Sphere Coating : The coating within the inside surface of the sphere must be a very efficient diffuse coating with high reflectance in order to deliver consistent integration and low absorption loss. Spectral Products uses a proprietary coating (ReflectraSpec) to provide high diffuse reflectance of light over a wide wavelength range. ReflectraSpec is effective from 400nm up to 2500nm. For 500nm to 20μm applications, diffuse AuSpec gold-coated spheres are available. For 180-400nm UV applications please contact Spectral Products regarding our new UVSpec coating.

  • Sphere Size: The inside diameter of the sphere must be a minimum of 1.5 times larger than any device mounted within the sphere such as light source, sample or detector.

  • Ports : No more than 5% of a sphere internal surface area should be used for ports in order to provide proper sphere integration. If the number of ports exceeds 5%, a larger sphere should be considered. Contact Spectral Products for help determining surface to port area.

  • Applications: Integrating spheres are used in many scientific research and industrial applications such as:

- Color Measurements

- Lamp Measurement Photometry

- Fluorescence Studies

- Reflectance of specular or scattering samples

- Laser &LED Measurements

- Uniform Light Source


Product Selection:

  Spectral Products offers a full line of standard integrating spheres.

ISC series are classical spherical type integrating spheres and they come standard with Ba2SO4 coating (effective from 400nm-2400nm and four orthogonal ports. Wall construction is cast aluminum (allows use of set screws). ISQ series use the heavy duty construction. Each sphere is composed of two halves, each machined from solid aluminum stock. Like ISC series, standard ISQ spheres come with Ba2SO4 coating, four orthogonal ports. Sphere can sit flat on work surface or be mounted on an optical mount post.
Depending on the application situation, some port plugs, port reducers, or a fiber adapter can be provided. The available models are as follows.

MODEL ISC Series ISQ Series
ISC-020 ISC-040 ISC-060 ISQ-020 ISQ-040 ISQ-060
DIAMETER 2" 4" 6" 2" 4" 6"
PORT SIZE 0.5" 1.0" 1.5" 0.5" 1.0" 1.5"

How to Select and Size an Integrating Sphere

In order to select the Spectral Products Integrating Sphere that is best suited for your application, several factors must be taken into consideration.
The most important factors include the following:
Diameter/Source Ratio The diameter of the sphere should be at least 1.5 times the largest dimension of any device mounted within the sphere.
Surface-to-Port Area If ports cover more than 5% of the Integrating Sphere's surface, the Integrating Sphere may not integrate properly. If port requirements are greater than 5% of the sphere, a larger sphere should be purchased.
The following formulas can determine port area and sphere surface area:
• r = Port radius, D = Sphere Diameter
• Port Area = pr2
• Sphere Surface Area = 4pD2Integrating Sphere Coatings The coating of a Spectral Products Integrating Sphere is a high efficiency diffuse reflector that delivers reliable integration and low throughput loss. The reflectance is high in order to minimize absorption loss from multiple reflections, yet it must not reflect light specularly.
Spectral Products Integrating Sphere Coatings offer reflectance efficiencies between 95 and 99%. A Lambertian Source is a perfect diffuse source. When a perfect diffuse reflector is illuminated with uniform intensity, it acts as a Lambertian Source. Spectral Products uses a proprietary Ba2SO4 coating, effective from 380 up to 2400 nm, to provide these state-of-the-art Lambertian properties.