Optical power measurements use the unit dBm, with the "m" denoting the reference power, set at 1mW. Input Value: 1 dBm Conversion Reference: Note: For power levels in dBm, positive values represent power > 1 mW, negative values represent power < 1 mW. Other general purpose light power measuring devices are usually called radiometers, photometers, laser power. Typical power levels measured by an optical power meter: Telecom transmitters: 0 to +10 dBm (1 to 10 milliwatts), Receivers: -30 dBm (1 microwatt) DWDM systems with fiber amplifiers: +10 to +20 dBm (10 to 100 milliwatts), Receivers: -20 to -30 dBm (1-10 microwatt) Data links and LANs: 0 to -10 dBm. Simply put, optical power is the "brightness" or "intensity" of light. In optical fiber networks, the units of optical power are often expressed in milliwatts (mw) and decibel milliwatts (dbm). The relationship is: 1mw=0dbm, that is to say, 2mw=3dbm, 10*lgmw is the dbm value.
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