Self-illuminated and Self-synchronized Image Up-conversion system by SHG based on a Passively Q-Switched Laser with an Intra-cavity Telescopic Configuration

We present a self-illuminated and self-synchronized image up-conversion system with an average power enhancement in the up-converted image. It is based on a Nd3+:YVO4+V3+:YAG passively Q-Switched laser at 1342 nm. The system provides up-conversion of an infrared image to its second harmonic by intra-cavity SHG in a KTP crystal. Although Q-switching a given continuous-wave laser leads to lowering its average power, we have derived a condition to achieve an enhancement in the average power of the up-converted image. To check experimentally the condition derived, we make use of an intra-cavity telescope that allows fulfilling the condition without affecting image resolution.