Design, Fabrication, and Characterisation of a Label-Free Nanosensor for Bioapplications.

In this paper, we present a hybrid semiconductor structure for biosensing applications that features the co-integration of nanoelectromechanical systems with the well-known metal oxide semiconductor technology. The proposed structure features an MOSFET as a readout element, and a doubly clamped beam that is isolated from the substrate by a thin air gap, as well as by a tunnel oxide layer. The beam structure is functionalised by a thin layer of biotargets, and the main aim is to detect a particular set of biomolecules, such as enzymes, bacteria, viruses, and DNA/RNA chains, among others. In here, a three-dimensional finite element analysis is performed in order to study the behaviour of the functionalised, doubly clamped beam. Preliminary results for the fabrication and characterisation processes show good agreement between the simulated and measured characteristics.

All-fiber laser with simultaneous Tm3+ passive Q-switched and Ho3+ gain-switched operation.

We experimentally demonstrate simultaneous Tm3+ passive Q-switched (PQS) and Ho3+ gain-switched laser operations at 1888.8 and 2021.2 nm, respectively, in a single-cavity all-fiber laser. The PQS operation of the Tm3+ laser is based on the use of a high-concentration holmium-doped fiber as a fiber saturable absorber. Then the Tm3+ laser emission is used as a pulsed pump source to achieve Ho3+ gain-switched pulses. A high birefringence fiber optical loop mirror used as a spectral filter allows the tuning of both Tm3+ and Ho3+ laser emissions.