Efficiency and Bandwidth in Electro-Optic Transduction

This technical note examines how efficiency and bandwidth are measured in microwave-to-optical electro-optic transducers. It compares published results and distinguishes photon conversion at the device ports from efficiency across the full link, which includes input and output losses. In an illustrative two-mode model, two operating points yield the same peak photon conversion efficiency of 36% but have bandwidths of 1.34 MHz and 4.25 MHz. The example shows why peak efficiency and bandwidth should be reported together when comparing transducers.