Super-Resolution Patterns in Quantum Dots

In this research, quantum dots and other materials were measured for their ability to absorb nonlinearly. Using the second harmonic of a nanosecond Nd: YAG laser an interference pattern was etched onto a quantum nanoparticle thin-film sample and a reference sample which were then compared against linear and nonlinear absorption. After one pattern was formed, a second pattern was interlaced with the first by introducing a phase shift into one arm of the interferometer. Due to the nonlinear nature of the absorption, this allows the formation of a pattern with twice the resolution possible with linear techniques. While the visibility of the combined pattern is reduced as compared to simple interference, it is still sufficiently high for many applications.