A silicon-based quantum dot random laser

Abstract

A silicon-based quantum dot random laser fabricated by a metal-assisted chemical etching method.

Ultralow Threshold Cavity-Free Laser Induced by Total Internal Reflection

“…Quite interestingly, the threshold pumping energy density of the laser, based on such colloidal CdSe/ZnS core–shell QDs of different emission wavelengths as the gain media, can be as low as ∼20 μJ cm –2 . To the best of our knowledge, it is the lowest threshold pumping energy density ever reported among all random lasing systems based on the colloidal QDs as the gain media. − The low threshold value is a result of the formation of coherent closed loops because of multiple scatterings in which the total internal reflection of the emitted light results in almost no energy loss during the multiple scattering processes.…”

“…To the best of our knowledge, it is the lowest threshold pumping energy density ever reported among all random lasing systems based on the colloidal QDs as the gain media. 34 − 38 The low threshold value is a result of the formation of coherent closed loops because of multiple scatterings in which the total internal reflection of the emitted light results in almost no energy loss during the multiple scattering processes.…”

Metal-assisted chemical etching beyond Si: applications to III–V compounds and wide-bandgap semiconductors

“…With catalyst patterning at the substrate level, via photolithography or other processes such as self-assembly 6 or electroless metal deposition, 7 a high degree of control over etched features can be exerted. Top-down processing through MacEtch has been explored for the fabrication of diverse structures including nanowire arrays, 8,9 nanofins, 10 microtrenches, 11 curved 12,13 and other arbitrary 14 features and a range of applications such as photonic crystals, 15 X-ray optics, 16 FinFETs, 17 solar cells, 18,19 lasers, 20 LEDs, 21 buried optical transmission gratings, 22 energy storage devices, 23 and sensors. 24,25 The mechanism responsible for MacEtch has not been fully elucidated, and etch progression varies based on etch system and substrate, but the broadest, most widely supported MacEtch model describes a three-phase process that occurs at a much faster rate in regions with both direct metal-to-substrate contact and sufficient solution access.…”

Recent progress and prospects of random lasers using advanced materials

“…Therefore, it renders RLs as an attractive platform for many applications such as cancer diagnostic 10,11 , Photonic barcodes 12 , a random spectrometer on a chip 13 , speckle-free bio-imaging 14 , speckle-free pulsed imaging technique 15 , sensing 16,17 , optical batteries 18 and optomicrofluidics 19,20,21 . The first type of RLs were dye-based colloidal systems 4,22 and then on many other systems like photonic crystals [23][24] , semiconductors 25,26,27 , quantum dots (QDs) 28,29 , polymeric matrices [30][31] , biological tissues 32 , rare-earth-doped nanopowders 33 , cold atoms 34 , etc. were introduced in the field.…”

“…The first type of RLs were dye-based colloidal systems 4,22 and then on many other systems like photonic crystals, 23,24 semiconductors, 25–27 quantum dots (QDs), 28,29 polymeric matrices, 30,31 biological tissues, 32 rare-earth-doped nanopowders, 33 cold atoms, 34 etc. were introduced in the field.…”