Quantum dots lase in levitated microdrop

June 1, 2008
By levitating a spherical liquid microdrop doped with quantum dots in an electrodynamical trap and accessing the droplet’s surface-resonant modes, researchers at the Max-Planck Research Group and University Erlangen-Nuremberg (Erlangen, Germany) have managed to make a quantum-dot microdrop laser.

By levitating a spherical liquid microdrop doped with quantum dots in an electrodynamical trap and accessing the droplet’s surface-resonant modes, researchers at the Max-Planck Research Group and University Erlangen-Nuremberg (Erlangen, Germany) have managed to make a quantum-dot microdrop laser. A 400× power enhancement is observed in the surface-lasing modes as compared to the photoluminescence emission spectrum for the combined quantum-dot particles at the same wavelength.

Click here to enlarge image

The 9- to 40-μm-diameter microdrops—composed of water, 30%-by-volume glycerin to prevent evaporation, and a low concentration (1.3 to 2.6 μmoles) of cadmium selenide/zinc sulfide) core/shell quantum dots—are levitated in an electrodynamic endcap trap and pumped with a pulsed Nd:YAG laser (10 ns pulses, 10 Hz repetition rate). Single-mode lasing at 640 nm is observed in droplets less than 10 μm in diameter, while multimode lasing occurs in larger droplets. Incredibly, calculations based on a uniform distribution of quantum dots indicate that to achieve the nanowatt-level lasing signals observed, each quantum dot in the microdrop must contribute approximately 500 photons during a 10 ns pump pulse. The Erlangen team is now working toward understanding the lasing mechanism in more detail. Contact Jessica Mondia at [email protected].

Sponsored Recommendations

Demonstrating Flexible, Powerful 5-axis Laser Micromachining

Sept. 18, 2024
Five-axis scan heads offer fast and flexible solutions for generating precise holes, contoured slots and other geometries with fully defined cross sections. With a suitable system...

Enhance Your Experiments with Chroma's Spectra Viewer

Sept. 5, 2024
Visualize and compare fluorescence spectra with our interactive Spectra Viewer tool. Easily compare and optimize filters and fluorochromes for your experiments with this intuitive...

Optical Filter Orientation Guide

Sept. 5, 2024
Ensure optimal performance of your optical filters with our Orientation Guide. Learn the correct placement and handling techniques to maximize light transmission and filter efficiency...

Ensure Optimal Performance with Shortpass Filters

Sept. 5, 2024
Achieve precise wavelength blocking with our Shortpass Filters. Ideal for applications requiring effective light transmission and cutoff, these filters ensure optimal performance...

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!