High resolution 2D image upconversion of incoherent light

An optimized method for continuous wave 2-dimensional (2-D) upconversion of incoherent or thermal light is demonstrated and quantified. Using standard resolution targets a resolution of 200×1000 pixels is obtained. The suggested method is viewed in scope of modern CCD cameras operating in the near infrared (NIR) portion of the electromagnetic spectrum.

The key is optimization of the upconversion process. This include Quasi-Phase-Matching leading to higher effective nonlinearities and elimination of walk-off, an intra-cavity design enhancing the upconversion process, and finally the use of modern NIR CCD detectors. Furthermore, we discuss the exceptionally good depth of field possible for imaging systems based on the proposed method.