Real-time dynamics and cross-correlation gating spectroscopy of free-carrier Drude slow-light solitons

Optical solitons—stable waves balancing delicately between nonlinearities and dispersive effects—have advanced the field of ultrafast optics and dynamics,with contributions spanning from supercontinuum generation to soliton fission,optical event horizons,Hawking radiation and optical rogue waves,among others.Here,we investigate picojoule soliton dynamics in silicon slow-light,photonic-bandgap waveguides under the influence of Drude-modeled,free-carrier-induced nonlinear effects.Using real-time and single-shot amplified dispersive Fourier transform spectroscopy simultaneously with high-fidelity cross-correlation frequency resolved optical gating at femtojoule sensitivity and femtosecond resolution,we examine the soliton stability limits,the soliton dynamics including free-carrier quartic slow-light scaling and acceleration,and the Drude electron–hole plasma-induced perturbations in the Cherenkov radiation and modulation instability.Our real-time single-shot and time-averaged cross-correlation measurements are matched with our detailed theoretical modeling,examining the reduced group velocity free-carrier kinetics on solitons at the picojoule scale.

Efficient option pricing with a unary-based photonic computing chip and generative adversarial learning

In the modern financial industry system,the structure of products has become more and more complex,and the bottleneck constraint of classical computing power has already restricted the development of the financial industry.Here,we present a photonic chip that implements the unary approach to European option pricing,in combination with the quantum amplitude estimation algorithm,to achieve quadratic speedup compared to classical Monte Carlo methods.The circuit consists of three modules:one loading the distribution of asset prices,one computing the expected payoff,and a third performing the quantum amplitude estimation algorithm to introduce speedups.In the distribution module,a generative adversarial network is embedded for efficient learning and loading of asset distributions,which precisely captures market trends.This work is a step forward in the development of specialized photonic processors for applications in finance,with the potential to improve the efficiency and quality of financial services.

Silicon photonic platforms for mid-infrared applications [Invited]

Silicon photonic integrated circuits for telecommunication and data centers have been well studied in the past decade, and now most related efforts have been progressing toward commercialization. Scaling up the silicon-oninsulator(SOI)-based device dimensions in order to extend the operation wavelength to the short mid-infrared(MIR) range(2–4 μm) is attracting research interest, owing to the host of potential applications in lab-on-chip sensors, free space communications, and much more. Other material systems and technology platforms, including silicon-on-silicon nitride, germanium-on-silicon, germanium-on-SOI, germanium-on-silicon nitride, sapphireon-silicon, Si Ge alloy-on-silicon, and aluminum nitride-on-insulator are explored as well in order to realize low-loss waveguide devices for different MIR wavelengths. In this paper, we will comprehensively review silicon photonics for MIR applications, with regard to the state-of-the-art achievements from various device demonstrations in different material platforms by various groups. We will then introduce in detail of our institute's research and development efforts on the MIR photonic platforms as one case study. Meanwhile, we will discuss the integration schemes along with remaining challenges in devices(e.g., light source) and integration. A few application-oriented examples will be examined to illustrate the issues needing a critical solution toward the final production path(e.g., gas sensors). Finally, we will provide our assessment of the outlook of potential futureresearch topics and engineering challenges along with opportunities.