Why Homodyne and Heterodyne coherent receiver has same SNR under shot noise limited?

Here is how I think: 1. Homodyne needs to split the light into two branch of BPDs; ->1/2*P_signal due to 3dB coupler. 2. Heterodyne has intermediate frequency; -> 1/2*P_signal due to cos/sin...

28 March 2017 4,958 1 View