The Series 99 amplified photodetector modules from Martin, Froeschner & Associates were designed for capturing fast transient light signals with optimal fidelity in the time domain. These compact devices have sensitivity down to the microwatt level, flat response from DC to >7 GHz and a gentle roll-off with usable responsivity to >10 GHz. They are true DC-coupled and are powered by internal batteries. They require no external power connections and can be connected directly to an input jack on a scope without fear of breakage. The spectral range for the InGaAs version is from 850 to 1750 nm. A number of options also are available.