Lasing by Template?Assisted Self?Assembled Quantum Dots

Miniaturized laser sources with low threshold power are required for integrated photonic devices. Photostable core/shell nanocrystals well suited as gain material and their properties can be exploited by direct patterning distributed feedback (DFB) lasers. Here, the 2nd-order DFB resonators tuned to photoluminescence wavelength of QDs used. Soft lithography based on template-assisted colloidal self-assembly enables pattern resolution in subwavelength range. Combined directional Langmuir–Blodgett arrangement, control waveguide layer thickness is further achieved. It shown that a lasing 5.5 mJ cm?2 reached printing method, which reduced factor ten (0.6 cm?2) at an optimal thickness. Moreover, it discussed how one adjust geometries any working wavelength. This approach offers prospects applications bioimaging, biomedical sensing, anti-counterfeiting, or displays.