Yes, in general SLEDs are sensitive to optical back-reflections. Due to EXALOS innovative design our SLEDs can still be operated under optical feedback and do not get damaged. However, optical feedback of lower than -35dB is generally recommended in order to fully guarantee the specifications. Higher values of optical feedback can induce modifications to the spectral density distribution and reduce output power. The use of an optical isolator with isolation > 30dB over the operational wavelength band is recommended. Without an optical isolator, the use of angled fiber connectors is necessary for optimal device performance. It is worth noting that the degree of sensitivity to back-reflection also depends on the state of polarisation of the returned light. Please download our Applications Notes for more details.