• Laser Targets
• Light Traps
• Transmissive Diffusers
• Port Adapters
• Detector Adapters

Laser Targets

Laser targets are used to diffuse an incoming laser beam in laser power measurements. If the beam is allowed to impinge on the sphere wall, two problems may arise. The first is that a 'hot spot' may form due to poor diffusion of the beam, resulting in erroneously high power readings. The second is that repeated exposure of the sphere wall to high laser flux may result in damage to the coating at the point of impact.

Laser targets are available in two configurations. The first, employing Fluorilon-99 as a target, effectively diffuses the laser beam. Fluorilon has a significantly higher laser damage threshold than standard sphere coating materials. These targets are ideal for UV-Vis-NIR lasers. The second target employs Avian Technologies diffuse gold coating. These targets are ideal for mid-IR (>2.5µ) lasers. Targets are a 45 degree cone that project into the sphere. Laser targets are designed to fit standard 1" ports and replace port plugs for laser power applications.

Laser Target

Light Traps

Light traps are useful for eliminating stray light in optical systems. They may be used as beam dumps, to determine the sphere zero (radiation that does not illuminate the sample but rather illuminates the sphere wall), remove the directly transmitted component in turbidity measurements, and to perform specular component subtraction in color measurement.

Light traps can be made in many configurations. Two of the most effective are the so-called "Clarke-Compton" light trap and the black cone light trap. The Clarke-Compton trap, developed by Frank J.J. Clarke and Anne Compton at the National Physical Laboratory, UK, consists of two black glass wedges at a 45 degree angle to each other inside of a black box. The multiple internal bounces off the black glass quickly reduce the returning radiation to a minimal level. Typically, the reflectance of a Clarke-Compton light trap is under 0.1%. The second is a cone inside a cylinder. Both the cone and cylinder are coated with a very low reflectance coating. The cone serves to scatter the incoming beam onto the cylinder surface. The reflectance of such cone light traps is higher than the black glass, but still well under 1%, but these traps can be used over a much wider wavelength range, extending into the mid-IR with the proper coating.

The light traps are designed to fit a standard 1" diameter port frame. They are compact in design, extending no more than 2" beyond the sphere surface.

Black Glass Light Trap:

Cylinder Light Trap:

Transmissive Diffusers

Transmissive diffusers scatter incident light. This reduces the sensitivity of a detector system to changes of angle or beam shape in the incoming beam. They can also be used outside of sphere applications to diffuse an incident directional beam and make it more uniform (although not as well as an integrating sphere) Avian Technologies diffusers are produced from thin, low density sintered PTFE and, unlike Opal Glass, can be used into the UV. Transmittance of the diffusers is appx. 25-30% in the visible but the output is very lambertian.

*May also be fitted to 1/4-20 optical boss for bench top use with appropriate mount.

Port Frame Reducers

Port frame reducers allow the user to decrease the size of any port to a smaller size. These are useful for the measurement of reflectance or transmittance of small samples. The port frame reducers fit standard 1" ports and reduce the sphere aperture to either 5, 10. or 15 mm diameter. The parts are made from anodized aluminum and coated on the sphere side with either Avian-B Barium Sulfate coating or Avian-D coating

* Gold port frame reducers are available on special order. Call for pricing.

Detector Holders

Detector holders are configured to mount a standard silicon detector in any standard Avian Technologies 1" port frame. The anodized aluminum part has a small set screw to hold the detector in place. The inside of the detector holder is painted with a flat black paint to act as a baffle and reduce stray light.

* Gold detector holders are available on special order. Call for pricing.