Hello All I have a question regarding the SNR of an optical signal The optical signal was measured with a FFT Spectrum analyzer with the amplitude in dBV - the "SNR" was observed to be 60dB (peak value in dBV - noise floor value in dBV = "SNR" in dB) The SNR is typically reported as the signal to noise ratio for power and not voltage. I was having a discussion with my boss about this and he was saying the the SNR in power could be reported as 120dB since there is a factor of two difference between the formula for dBV (w.r.t. V) and dBm (w.r.t. mW). Although I can see his resoning, this seemed odd to me as other measurement (made in power) suggest that the SNR is not 120dB, however, the other measurements were made with spectrum analyzers that are not as good as the FFT spectrum analyzer (which measures in dBV). I was just hoping someone could give some insight on this. Cheers and thanks.