Second-harmonic-enhanced feedforward laser-intensity-noise stabilization

Quantum nondemolition theory has been well understood for a number of decades, however, applications of such techniques remain limited owing to the increased complexity that these techniques require. In this paper, quantum nondemolition theory is used to investigate the performance of a real-world device, an electro-optic feedforward intensity-noise eater. It is shown that by replacing the typical beam splitter in such a device with a single-pass second-harmonic generation followed by a dichroic mirror the performance of the noise eater can be significantly improved, even with low conversion efficiencies.