The 1414-50 High Speed Multimode Fiber-Optic Detector has a flat response in both amplitude and phase up to 25 GHz and are optimized for frequency-domain applications. The high-sensitivity near-IR photodetector uses a 25 μm diameter back-illuminated InGaAs Schottky photodiode with a peak responsivity of 0.5 A/W at 1300 nm. The active layer is twice as thick as in our ultrahigh-speed Model 101X module, producing a 50% greater responsivity over its 850 to 1630 nm wavelength range. The conversion gain with a 50 Ω load is 14 V/W. It has an FC/UPC 50 μm multimode input.