![*Divergent Light Measurement](https://d27wgn5g4t3wja.cloudfront.net/img/e2465fd0-1422-08df-aa9a-d8f04abd69fe/272574.png)
*Divergent Light Measurement
The IS1.5-VIS-FPD-800 & IS1.5-IRG-FPD-800 contain 2 photodiodes: a calibrated photodiode for precise power measurement using Ophir meters and a fast photodiode with integral reverse bias circuit for temporal characterization using third-party instrumentation such as oscilloscopes and spectrum analyzers. Their small, 1.5" internal diameter preserves the temporal shape of pulses down to 3.5 nsec for VIS and 6 nsec for IRG. An SMA fiber optic connector is provided for connection to a spectrometer. The large, 20 mm input aperture allows for wide acceptance angles and long working distances, making these spheres well suited for testing VCSELs and other types of laser.