This presentation discusses the recent results on miniaturized pulsed solid-state lasers by utilizing femtosecond-laser inscribed crystalline channel waveguides and carbon-nanomaterial-based saturable absorbers. Based on optical characterization and optimization of the optical materials, integrated compact waveguide lasers present diverse pulsed operation regimes from Q-switching to continuous-wave mode-locking. Pulsing mechanism and various parameters in waveguide lasers are investigated to provide a basis for achieving higher performance of novel on-chip ultrafast lasers.

We present the fabrication of transverse graphitic microelectrodes in a 500 micrometer thick synthetic diamond bulk by means of pulsed Bessel beams. By suitably placing the elongated focal length of the Bessel beam across the entire sample, the graphitic wires grow from the bottom surface up to the top during multiple shot irradiation. The morphology of the microstructures generated and the micro-Raman spectra are studied

as a function of the laser parameters and the diamond crystal orientation. We show the possibility to generate high conductivity microelectrodes, which are crucial for the application of electric fields or current transport/collection in various chips and detectors.

Selective Solar Absorbers (SSAs) are the critical element of high-vacuum flat plate collectors, as these are subject to elevated operating temperatures and thus experience high radiation losses. Here we design and optimize an SSA based on a multilayer design made of HfCx, Si3N4, and SiO2 layers. The structure of the proposed SSA has been optimized to maximize the solar-to-thermal energy conversion efficiency in high vacuum solar thermal panels working at 200 °C, reaching thermal emissivity values much lower than absorbers currently available on the market (<0.02 Vs >0.07) and obtaining unprecedented performances.

Lattice plasmon lasers demonstrated to have many degrees of freedom useful to tailor the lasing properties, as the tuning of the morphological properties of the array or the coupling of proper emitters to band edge states of the plasmonic crystal. Here, we present the results of the study of the lasing emission properties of a hexagonal array of aluminum nanoparticles as a function of the pumping conditions. We demonstrate how the geometrical and dynamic features of the pumping system have a significant impact on the lasing properties without affecting the temporal coherence of the emission. Moreover, by combining different pumping systems and studies at different incidence angles, the relationship between nanoarray, dye and pump has been clarified.

We present PbS colloidal quantum dots (CQDs) as a promising new gain media for the fabrication of tuneable near- to mid-infrared laser sources. Using distributed feedback (DFB) cavities, we have demonstrated lasing within the telecommunication bands between 1.55 μm – 1.65 μm and have now extended this to gain media beyond 2 μm using large PbS CQDs. We have characterised these dots using transient absorption spectroscopy and amplified spontaneous emission, showing them to have a significantly lower gain threshold than their smaller counterparts (down to ~40 μJ/cm2).