The Tektronix TOP200 and TOP220, true palm-sized optical power meters, cover the full range of optical fiber applications. These instruments were engineered for field and lab personnel requiring a high performance, cost effective, compact and rugged OPM. The TOP200 and TOP220 optical power meters utilize the snap-on connector (SOC) interface. All industry-standard fiber-optic connectors can be accommodated via a complete line of snap-on connector adapters. The TOP200 and TOP220 design combines a state-of-the-art signal processor and microcomputer electronics to provide superb performance as well as simple and elegant operation with just three controls: ON/OFF, dBm/dB and X. Photonic energy is directly analyzed through digital signal processing. The result is a very fast readout settling time. The instrument settles within less than two seconds upon applying a OdBm power level. Quick readout stabilization becomes very important when performing repetitive measurements or splice alignment. The TOP220 has an optical filter in front of the photodetector to attenuate high power levels. This filter extends the range of the optical input power to +27dBm.