Fabrication and optical property characterization of quantum-dot-array diffraction grating with single order diffraction based on focused ion beam

Abstract

Quantum-dot-array diffraction grating(QDADG), with an area of 200 μm×200 μm, a line density of 500 line/mm, an aperture size of 800 nm and a gold absorber of 500 nm thick, is successfully fabricated by focused ion beams. The diffraction properties and relative diffraction efficiencies of QDADG are measured at different transfer distance for 442 nm laser. It is shown that the high-order diffraction is removed from the spectra with only the ±1 and 0 order diffraction lines reserved. Moreover, in accordance with the calculated values obtained using the grating equation, variations of space between the 1st order and the 0th order increase gradually with the increase of transfer distance.