Direct coupling of the optical field in a ∼244 nm thick, CdSe/ZnS quantum dot film to an optical fiber has yielded lasing in the red (λ ∼ 644 nm) with a threshold pump energy density < 2.6 mJ cm-2. Comprising 28-31 layers of ∼8 nm diameter quantum dots deposited onto the exterior surface of a 125 μm diameter coreless silica fiber, this free-running oscillator produces 134 nJ in 3.6 ns FWHM pulses which correspond to 37 W of peak power from an estimated gain volume of ∼4.5 × 10-7 cm3. Lasing was confirmed by narrowing of the output optical radiation in both the spectral and temporal domains, and the laser beam intensity profile approximates a top hat.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)