Abstract

We present a mid-infrared optical parametric chirped-pulse amplifier (OPCPA) system based on aperiodically poled Mg:LiNbO₃ (APPLN) [1]. Arbitrarily broad bandwidth is possible because the grating provides a range of k-vectors, phase matching all frequencies of interest. The grating can be engineered to overcome spectral gain narrowing, tailor the group delay dispersion (GDD) over a large bandwidth, and improve efficiency with reduced back-conversion [2, 3]. We use a linearly chirped quasi-phase matching (QPM) grating to demonstrate a low-noise, high-power source. The transform limit of our 1.56 µm seed source (55 fs) is maintained through the amplification chain and transferred onto our mid-infrared idler in the second stage. An uncompressed output power of 1.4 W at 3.3 µm is achieved, with no signs for gain-narrowing (s. Fig. 1b).

© 2011 Optical Society of America