Ultrafast electron thermalization—the process leading to carrier multiplication via impact ionization1,2, and hot-carrier luminescence3,4—occurs when optically excited electrons in a material undergo rapid electron–electron scattering3,5–7 to redistribute excess energy and reach electronic thermal equilibrium. Owing to extremely short time and length scales, the measurement and manipulation of ...

Traditional sound sources and sound detectors are usually independent and discrete in the human hearing range. To minimize the device size and integrate it with wearable electronics, there is an urgent requirement of realizing the functional integration of generating and detecting sound in a single device. Here we show an intelligent laser-induced graphene artificial throat, which can not only ...

We demonstrate a simple, compact and low cost Q-switched erbium-doped fiber laser (EDFL) exploiting a graphene saturable absorber (GSA) for possible applications in metrology, sensing and medical diagnostics. The EDFL operates at 1560 nm with repetition rates of 31.3 kHz and 25 kHz with GSA1 and GSA2, respectively, at pump power of 120 mW. The repetition rate is smaller with a lower pump power....

We report an unusual enhancement of the Raman signal of the G mode in a twisted graphene bilayer (2-LG) on a hexagonal single-crystalline boron nitride substrate. We used an isotopically engineered 2-LG, where the top layer was composed of (13)C atoms and the bottom layer of (12)C atoms. Consequently, it was possible by Raman spectroscopy to distinguish between the enhancement coming from the t...

Ultrafast materials science promises optical control of physical properties of solids. Continuous-wave circularly polarized laser driving was predicted to induce a light-matter coupled state with an energy gap and a quantum Hall effect, coined Floquet topological insulator. Whereas the envisioned Floquet topological insulator requires high-frequency pumping to obtain well-separated Floquet band...

In this paper, we present an Yb-doped Y2O3 waveguide laser fabricated by pulsed laser deposition (PLD) that is Q-switched using a mono-layer graphene saturable absorber. 140 ns pulses at a repetition rate of 1.21 MHz and pulse energy of 14 nJ are achieved at an absorbed pump power of 528 mW. Introduction: Pulsed lasers have a range of applications in areas such as medicine, material processing,...

Polarization rotation vector solitons formed in a fiber laser passively mode locked with atomic layer graphene were experimentally investigated. It was found that different from the case of the polarization locked vector soliton formed in the laser, two extra sets of spectral sidebands always appear on the soliton spectrum of the polarization rotating vector solitons. We confirm that the new se...

We present an all-graphene based open microfluidic manufacturing technique by manipulating the surface wettability of spin-coated graphene ink films via laser-controlled patterning. The approach is rapid, flexible, and opens diverse applications in fluid transport.

Research on hybrid graphene with other two-dimensional materials has gained considerable attention owing to their potential applications beyond single components. Through our first principles analysis via density functional theory, graphene-molybdenum disulphide (MoS2) demonstrated a band gap opening by 2 meV, from gapless when MoS2 layer is introduced into the structure. The simulated graphene...

We report a simple, handy and affordable optical approach for precise number-oflayers determination of graphene on SiC based on monitoring the power of the laser beam reflected from the sample (reflectance mapping) in a slightly modified micro-Raman setup. Reflectance mapping is compatible with simultaneous Raman mapping. We find experimentally that the reflectance of graphene on SiC normalized...