Enhanced thermal conduction by surface phonon-polaritons.

Improving heat dissipation in increasingly miniature microelectronic devices is a serious challenge, as the thermal conduction in nanostructures is markedly reduced by increasingly frequent scattering of phonons on the surface. However, the surface could become an additional heat dissipation channel if phonons couple with photons forming hybrid surface quasiparticles called surface phonon-polaritons (SPhPs). Here, we experimentally demonstrate the formation of SPhPs on the surface of SiN nanomembranes and subsequent enhancement of heat conduction.

Extended cavity quantum cascade laser with cavity resonator integrated grating filter.

We report on an extended cavity quantum cascade laser based on a cavity resonator integrated grating filter (CRIGF) that acts as both cavity end-reflector and spectral selector. Stable, mode-hop free, single-mode emission around 2150 cm is obtained over large injection current ranges (more than 50 mA) with a typical threshold around 290 mA. A digital frequency tuning over more than 65 cm is obtained by changing the periodicity of the CRIGF ending the extended cavity.

Thermal Conductivity Reduction in a Silicon Thin Film with Nanocones.

Modern thermoelectric devices incline toward inexpensive, environmentally friendly, and CMOS-compatible materials, such as silicon. To improve the thermoelectric performance of silicon, researchers try to decrease its thermal conductivity using various nanostructuring methods. However, most of these methods have limited efficiency because they are costly and damaging for the internal structure of silicon.

Probing ballistic thermal conduction in segmented silicon nanowires.

Ballistic heat conduction in semiconductors is a remarkable but controversial nanoscale phenomenon, which implies that nanostructures can conduct thermal energy without dissipation. Here, we experimentally probed ballistic thermal transport at distances of 400-800 nm and temperatures of 4-250 K. Measuring thermal properties of straight and serpentine silicon nanowires, we found that at 4 K heat conduction is quasi-ballistic with stronger ballisticity at shorter length scales.

Mid-infrared cavity resonator integrated grating filters.

Cavity Resonator Grating Filters (CRIGFs) working in the Mid-Infrared are reported, with narrow-band resonant reflectivity peaks around 2200 cm (4.6 µm). They are fabricated in the GaAs/AlGaAs material system that can potentially cover the whole [1-12] µm spectral range.