The 1414 High Speed Fiber-Optic Detector shows a flat response in both amplitude and phase up to 25 GHz and are optimized for frequency-domain applications. This near-IR photodetector uses a 25 μm diameter back-illuminated InGaAs Schottky photodiode with peak responsivities of 0.6 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 500 to 1630 nm wavelength range. The conversion gain with a 50 Ω load is 17 V/W. It has a FC single-mode input and Wiltron K electrical output. The detector uses a internal 9-V battery.