Anisotropic nonlinear optical response in a graphene oxide-gold nanohybrid.

In this Letter, we report for the first time, to the best of our knowledge, the anisotropic optical response in a graphene oxide (GO)-gold (Au) nanohybrid. Polarization-sensitive nonlinear optical absorption measurements revealed that nanohybrids are highly anisotropic, (ß⊥-ß‖)≈28cm/GW, which is more than one order of magnitude higher than that of control GO (2 cm/GW). The first-principle analysis of absorbance at nanohybrid interfaces with varying functional ligand concentrations corroborates with the experimentally observed intrinsic linear anisotropy. Thus, this Letter enables new routes to realize smart and high-performing nonlinear optical systems selectively and directionally such as tunable optical limiters and optical data processing devices.

Gender and age based differences in behavioural patterns following anterior cruciate ligament injury.

ACL injury can be clinically diagnosed prior to imaging, and therefore understanding any symptomatology differences between age-groups and genders is critical. Data gathered from 341 patients with ACL injuries over six years showed no gender-based difference in ability to continue playing sport post-injury. Fewer males required crutches (37.2% vs. 49.5%, p = 0.04) and more males returned to sports prior to treatment (24.4% vs. 14.1%, p = 0.04). There was no age based difference in play continuation post-injury, however more elderly patients fell post-injury (<30 y: 91.9%, 30 y 83.8%, p = 0.02). Therefore, there are few differences in behavioural patterns following ACL injury based on age or sex.

Saturable absorption in one-dimensional Sb2Se3 nanowires in the visible to near-infrared region.

One-dimensional (1D) free-standing nanowires are particularly important for carrier confinement in two dimensions, which provides a platform to explore the nonlinear optical phenomena at the nanoscale. In this Letter, we demonstrate saturable absorption in the resonant and above-bandgap excitations of both ns and fs pulses in 1D crystalline Sb2Se3 nanowires prepared by the facile hydrothermal method. Impressively, the average length of the nanowires extends to a few micrometers with a high aspect ratio of 300. The excited-state to ground-state absorption cross-section ratio in Sb2Se3 nanowires is ≈0.23, which suggests that they can be utilized as passive mode lockers.

Tuning nanosecond transient absorption in a-Ge25As10Se65 thin films via background illumination.

In this Letter, we report for the first time, to the best of our knowledge, continuous-wave laser background illumination (BGI) as a simple and yet useful tool to tune nanosecond transient absorption (TA) in a-Ge25As10Se65 thin films. In our experiments, we observed remarkable blueshift in TA as a function of the BGI intensity. Strikingly, relaxations of TA in background-illuminated samples are much faster than the as-prepared samples. This observation provides new insights into the bond-breaking mechanism. Further, decay time constants of TA are wavelength dependent, which signifies that excited carriers have a longer lifetime in deep traps than in shallow traps.