Highly efficient parametric amplification of optical beams. II. Parametric interaction of waves with conformal profiles

Design of a highly stable, high-conversion-efficiency, optical parametric chirped-pulse amplification system with good beam quality

“…The maximum OPCPA conversion efficiency is obtained when the rate of energy transfer from the pump to the signal and idler is such that all spatial and temporal points in the pulse reach peak conversion simultaneously. Maximizing the conversion efficiency thus requires the use of complementary shapes for the seed and pump spatial and temporal profiles, as described by Begishev et al 8,9 Appropriate seed temporal shapes can be approximated by spectral shaping 10 or other pulse-shaping techniques. 11,12 Ross et al 12 described a multiple-stage OPCPA design that allows significant reconversion in the preamplifier stages in order to produce an approximately complementary seed shape for use with a temporally Gaussian shaped pump in the final power-amplifier stage.…”

High-conversion-efficiency optical parametric chirped-pulse amplification system using spatiotemporally shaped pump pulses

“…This has several implications: First, careful tailoring of the pump and seed spatiotemporal profiles is required to achieve high optical parametric amplification (OPA) conversion efficiency. 6,7 Second, even slight variations in the pump intensity can result in large amplification-factor fluctuations, potentially leading to significant spatial and spectral modulation and large overall energy fluctuations in the amplified broadband output pulse. It has been shown that, for a narrow range of pump intensities and a particular interaction length, saturation in the OPA process can be observed, reduc-…”

Optimization of high peak power few-cycle optical parametric chirped pulse amplifier systems

“…Depletion of an arbitrarily shaped pump can be enhanced by using conformal profiles for the interacting waves [107,108]. During this method the spatiotemporally shaped signal has a complementary shape of the pump pulse, which results in equalized signal gain and pump depletion at every spatial and temporal coordinate.…”

“…They indicate that the central part of the pump is almost reconverted and the depleted region is moved towards the peripheries, which means that more energy is extracted from those parts than in a conventional OPA. It can be also noted that the pump and signal shapes are conformal [108], which ensures high efficiency in the second crystal. The spatial and temporal shape of the pump and signal pulses after the second crystal in Case 1 are plotted in Fig.…”