Polarization-based idler elimination: enhancing the efficiency of optical parametric amplification

This study presents a novel way to increase the energy conversion efficiency of optical parametric amplification by eliminating the idler wave from the interaction using consecutive type-I and type-II amplification processes. By using the aforementioned straightforward approach the wavelength tunable narrow-bandwidth amplification with exceptionally high 40% peak pump-to-signal conversion efficiency and 68% peak pump depletion was achieved in the short-pulse regime, while preserving the beam quality factor of less than 1.4. The same optical layout can also serve as an enhanced idler amplification scheme.