Researchers Trap Infrared Light in Ultra-Thin Molybdenum Diselenide Layer

Key facts

• Researchers from the University of Warsaw, Lodz University of Technology, Warsaw University of Technology, and the Polish Academy of Sciences developed a nanoscale structure to trap infrared light.
• The structure uses a layer of Molybdenum Diselenide (MoSe2) that is 40 nanometres thick, which is over 1,000 times thinner than a human hair.
• The design employs a subwavelength grating consisting of closely spaced parallel strips that act as a near-perfect mirror to confine light.
• Molybdenum Diselenide (MoSe2) was selected for its high refractive index, which slows light down by approximately 4.5 times compared to 1.5 times in glass.
• The structure facilitates third harmonic generation, a nonlinear optical process that combines three infrared photons to produce one visible blue light photon.
• The light conversion efficiency in this nanoscale structure is more than 1,500 times stronger than in a flat layer of the same material.
• The research team utilised Molecular Beam Epitaxy (MBE) to produce large, uniform films of MoSe2, overcoming the limitations of the traditional exfoliation method.
• The findings of the study were published in the scientific journal ACS Nano.