Why is it essential to use a calibrated light source and optical power meter when conducting insertion loss measurements?

It is essential to use a calibrated light source and optical power meter when conducting insertion loss measurements to ensure accurate and reliable results. Insertion loss is the amount of optical power lost as a signal travels through a component or a section of fiber. A calibrated light source provides a stable and known optical power at a specific wavelength. Calibration ensures that the light source is emitting the power level indicated on its display, minimizing errors in the measurement. A calibrated optical power meter is used to measure the optical power at the receiving end of the component or fiber. Calibration ensures that the power meter is accurately measuring the optical power, taking into account the detector's responsivity at the specific wavelength. Using uncalibrated equipment can lead to significant errors in the insertion loss measurement. For example, if the light source is emitting a power level that is different from what is indicated, the insertion loss will be either over or underestimated. Similarly, if the power meter is not accurately measuring the power, the insertion loss will be incorrect. Calibration involves comparing the equipment's readings against a known standard and adjusting the equipment to match the standard. This ensures that the equipment is providing accurate and traceable measurements. To measure insertion loss accurately, a baseline measurement is taken by connecting the light source directly to the power meter and recording the power level. Then, the component or fiber under test is inserted between the light source and the power meter, and the new power level is recorded. The insertion loss is the difference between the baseline power level and the power level with the component inserted. Using calibrated equipment ensures that this difference accurately reflects the actual loss introduced by the component or fiber. Regular calibration of light sources and power meters is crucial for maintaining the accuracy of insertion loss measurements and ensuring the quality of fiber optic networks.