Collinear two colour Kerr effect based time-gate for ballistic imaging

A novel setup is presented for ballistic imaging using an efficient ultrafast Kerr effect based optical time-gate with gating times of the order of ~0.8 picoseconds. At first, the major drawbacks of the classical non-collinear optical setup are discussed. Then, the new collinear arrangement is proposed, which overcomes these issues and improves the achievable imaging spatial resolution and gate timings. Few preliminary results for ballistic imaging of liquid sprays/jets are presented for this arrangement. It is shown that using a solid state Kerr medium (GGG crystal), instead of the classical liquid CS$_2$, allows reduction in the opening time of the optical gate.