Unstressed receiver sensitivity testing is performed by simply connecting the transmitter to the receiver via a variable optical attenuator. BER values are recorded against different receiver power values and are finally plotted against each other. Keysight attenuators offer low insertion loss, low. Optical attenuators play a crucial role in ensuring the accuracy and reliability of optical sensors. To achieve a certain BER, the receiver sensitivity. Attenuators are essential building blocks when developing test stations for applications such as bit-error-rate (BER) testing of transmission cards or gain and noise characterization of erbium-doped fiber amplifiers (EDFAs). Exceeding the BER value indicates signal degradation, rendering it unsuitable for data communication.