Output optical power refers to the output optical power of the light source at the transmit end of the optical module. If the optical power is excessively high, the optical component may be burnt. Important Safety Note: The IEC 60825 laser safety standard defines Class 3R as. In this section, we will learn how to do the following things: Determine the gain of a laser ampli er Find the threshold gain of a cavity Predict the output power of a laser Determine the output mode of the laser Unless otherwise stated, steady state ( d = 0) behavior may dt be assumed. INTRODUCTION Accompanied by the widespread use. Optical power is measured in linear units of milliwatts (mW), microwatts (uW - really the greek letter "mu"W), nanowatts (nW) and decibels (dB).