Follow the links to read the full papers in the IET Digital Library.
Through a glass darkly
Research from Japan reports that Ca additive effectively suppresses the photo-darkening (PD) effect in Yb-doped silica fibre even at 6.0 wt% of high Yb2O3 concentration. With the Ca ion working as a stabiliser to maintain the Yb3+ valence state, such Yb-Ca co-doped silica fibre could be useful for high-power fibre lasers. The work also provides hints for a better understanding of the PD phenomenon.
A little heat
Samsung report fabrication of a highly conducting carbon nanotubes (CNTs) /
polydimethylsiloxane (PDMS) composite for electric heating unit applications. High shear processing techniques were used to separate highly entangled multi-walled CNTS and percolation threshold was found to be lower than previously reported at < 0.1 vol.%. The composites can be heated from 30 – 130 °C within 90 seconds using a 5V DC supply.
Feel the power
Work from Korea investigates the feasibility of energy harvesting using the human body as an antenna for low frequency band ambient EM waves. The research finds that this yields more power than using a general antenna to harvest power in high frequency bands and has the advantage of excellent portability.
In a high speed optical transmission system, the signal at the receiver needs to be demultiplexed to a lower tributary channel. For the first time, researchers in France have reported demultiplexing of a 170.8 Gb/s on-off keying signal in a chalcogenide microstructured fibre.
Display of power
Researchers in the UK have investigated the feasibility of obtaining high power microchip VECSELs with modal properties controlled by a grating aperture. These lasers are in great demand for applications ranging from pump sources, emitters for laser displays, laser-based spectroscopy or even cell manipulation using optical trapping.