Using Bessel beams and two-photon absorption to predict radiation effects in microelectronics

Laser photonic-reduction stamping for graphene-based micro-supercapacitors ultrafast fabrication

Micro-supercapacitors are promising miniaturized energy storage devices that have attracted considerable research interest. However, their widespread use is limited by inefficient microfabrication technologies and their low energy density. Here, a flexible, designable micro-supercapacitor can be fabricated by a single pulse laser photonic-reduction stamping. A thousand spatially shaped laser pulses can be generated in one second, and over 30,000 micro-supercapacitors are produced within 10 minutes. The micro-supercapacitor and narrow gaps were dozens of microns and 500 nm, respectively. With the unique three-dimensional structure of laser-induced graphene based electrode, a single micro-supercapacitor exhibits an ultra-high energy density (0.23 Wh cm⁻³), an ultra-small time constant (0.01 ms), outstanding specific capacitance (128 mF cm⁻² and 426.7 F cm⁻³) and a long-term cyclability. The unique technique is desirable for a broad range of applications, which surmounts current limitations of high-throughput fabrication and low energy density of micro-supercapacitors.

Microfabrication for cost-effective miniaturized energy storage devices remains a challenge. Here, the authors propose a spatially shaped femtosecond laser method, which is ultrafast, one-step, high resolution and large-scale, for use in patterning flexible high-performance micro-supercapacitors.

Nonlinear Optics: feature issue introduction

This joint issue of Optics Express and Optical Materials Express features 18 state-of-the art articles that witness actual developments in nonlinear optics, including those by authors who participated in the international conference Nonlinear Optics held in Waikoloa, Hawaii from July 15 to 19, 2019. As an introduction, the editors provide a summary of these articles that cover all aspects of nonlinear optics, from basic nonlinear effects and novel frequency windows to innovative nonlinear materials and devices, thereby paving the way for new nonlinear optical concepts and forthcoming applications.