Digital holography efficiency measurements with excess noise

In this paper, we use digital holography (DH) in the off-axis image plane recording geometry with a 532 nm continuous-wave laser to measure the system efficiencies (multiplicative losses) associated with a closed-form expression for the signal-to-noise ratio (SNR). Measurements of the mixing efficiency (36.8%) and the reference noise efficiency (74.5%) provide an expected total system efficiency of 22.7%±6.5% and a measured total system efficiency of 21.1%±6.3%. These total noise efficiencies do not include our measurements of the signal noise efficiency (3%-100%), which are highly dependent on the signal strength and become significant for SNRs>100. Thus, the results confirm that the mixing efficiency is generally the dominant multiplicative loss with respect to the DH system under test; however, excess reference and signal noise are significant multiplicative losses as well. Previous results also agree with these experimental findings.