This part of IEC 62150 specifies test and measurement procedures for relative intensity noise (RIN). It applies to lasers, laser transmitters, and the transmitter portion of transceivers. This procedure examines whether the device or module satisfies the appropriate performance. Semiconductor laser Relative Intensity Noise (RIN) is an important parameter that can cause significant degradation to the performance of fibre optic communications links. It is important for both laser manufacturers and systems designers in understanding how RIN is measured to ensure reliable. In the most basic definition RIN (Relative Intensity Noise) is a ratio of the laser's intensity noise to power. This is then typically expressed over the bandwidth of interest: BW = Low-pass bandwidth of an optical-electrical receiver system, or of the measuring system in. RL = Load resistance, impedance seen by the photodetector.
