We report a very high signal gain of 1.13 x 10(7) at a low pump intensity of 260 MW/cm(2) in a two-stage optical parametric chirped-pulse amplifier (OPCPA), which is used as a pre-amplifier for a short-pulse front-end Nd:glass high-energy laser system. A signal energy of 0.17 nJ was amplified to 2 mJ with a central wavelength of 1053 nm and a repetition rate of 10 Hz using the OPCPA with a 15 mm-long BBO crystal at optical parametric amplifier (OPA) stage 1 and a 12 mm-long BiBO crystal at OPA stage 2. (C) 2011 Elsevier B.V. All rights reserved.