High Resolved Non-Collinear Idler Imaging via Type-II Angular Noncritical Phase-Matching

This letter presents an angular noncritical phase-matching (PM) design in a non-collinear optical parametric amplifier to improve the spatial resolution of idler imaging. The design can not only promote the spatial gain bandwidth, but also eliminate the spatial walk-off between the Poynting vectors of the signal and the idler. By using an 800-nm pulse train as signal and its second-harmonic as pump, we have experimentally realized idler imaging with a two-dimensional space-bandwidth-product more than 72,900, which, to the best of our knowledge, is the highest value of the reported idler images to date.