Our flashed opal optical disk diffusers are significantly less expensive than integrating spheres and are easily mounted in a simple optic holder. Diffusers scatter incident light, thereby reducing the sensitivity of a detection system to slight positional or angle changes in an incoming beam. They can also be used to improve the uniformity of a light source. For many measurements, particularly of very low signals, optical disk diffusers are more practical and economical than other diffusing options.
Our diffusers have a thin diffusing glass coating bonded to a clear glass substrate. They are close to ideal in performance, which creates much "loss" for collimated beams as they are now scattered into 4π steradians. Our diffusers' spectral transmittance range is 400 to 2,000 nm, but since short wavelengths scatter more, these are better diffusers for the visible than for IR radiation.
1" and 1.5" diameter sizes are available.
To improve the uniformity of an Oriel Light Source, place one or more of these diffusers at its output. For high power sources (>200 W), use a liquid filter or dichroic mirror before the flashed opal diffuser to protect it from the high intensity.
Since some detectors vary in sensitivity across their photosensitive area, diffusers are used to reduce the dependence of signal on the incoming beam shape, position, and angular distributions. The tradeoff is that they also attenuate the signal. The amount of attenuation is dependent upon several factors:
- Detector area
- Distance from diffuser to detector (see illustration)
- Incoming beam size
- Diffuser spatial performance (i.e., How close to an ideal Lambertian is the diffuser?)
- Diffuser spectral transmittance (i.e., How much of the incident beam, at the wavelengths of interest, pass through the diffuser?)
When the diffuser is close to the detector (top view), it efficiently captures on-axis radiation, but the combination is sensitive to beam position. Very little radiation from ray B gets to the detector. In the bottom view, both rays A and B contribute to the detector signal. Sensitivity to position of the incoming light is reduced, but the signal is also reduced.
The diffusing properties of optical disk diffusers vary with wavelength. Use care when performing spectroradiometric measurements, as the diffuser will affect relative spectral distribution of light measured at any particular point in space.
Specifications
| Material |
Soda lime based material fusing low-iron glass and opalescent glass |
| Diameter tolerance |
|
| Thickness |
2.2 mm |
| Edge Finish |
Ground and beveled |
| Surface Quality |
Commercial Polish |
| Spectral transmittance range |
400-2000 nm |
The diffusing properties of optical disk diffusers vary with wavelength. Use care when performing spectroradiometric measurements, as the diffuser will affect relative spectral distribution of light measured at any particular point in space.
