Emission reception

A bare fiber connector is a reasonably valid emission receptor. Any emission in its field of view will be received and transmitted into the connected specrometer or accessory.

If the fiber is fixed in a single position its input can be used quantitatively. An example would be sensing the radiation reflected from a sample and then, with a standard white replacing the sample, the sample, then the ratio reflectance (percent reflectance) can be determined.

Note that the input field of view is 25° in a plane angle and 0.89 steradian in a solid angle.

For receiving radiance from a specific source, a collimating lens does the job. There are several lenses in the 74 series and one lens in the 84 series. Three of the 74 series lenses are encased in metal barels which are threaded to fit the typical SMA905 connectors on the end of fiber optic lines.

The inner barrel of these collimating lens assemblies can be adjusted to provide focus from converging to 45° FOV at f2 optical characteristics.

The larger collimating lens assembly, the 84 series is for coupling larged free space beams to fibers. This 84-UV-25 assembly (shown here) can collimate input light at distances to 10 meters.

Cosine correctors receive radiance from 180° plane angle (2π solid angle) for a close approxi­mation to area irradiation. The provides for light measurements both of relative and, when calibrated, absolute spectral intensities. The Cosine correctors are particularly useful for evaluating emissive color and for evaluating light sources.

A special cosine corrector is the CC-3-DA which is discussed below.

The CC-3-DA is a cosine corrector which is designed to be directly attached to the input connector of a miniature spectrometer. This at­tachment makes a spectrometer into a hand held spectroradiometer. The resulting combina­tion becomes highly useful for making genreal irradiance measurementrs, for making area light­ing surveys and for plant growth studies. Not only can it collec physical light information, but the data can be modified by photometric responses for luminous measurements and can also be related to photosythetic active radiation measurements. The use of it on a spectrometer makes the combination ideal for measurements where typical spectroradiometers don't fit, such as for under canopy reception.