A plasmonic sensor based on a metal–insulator–metal waveguide with a side-coupled nanodisk resonator is proposed and numerically investigated using a finite-difference time-domain method. The numerical simulation results indicate that more than one sharp resonance dip appears in the transmission spectrum in the telecommunication regime, and each resonance wavelength has a linear relationship with the refractive index of the dielectric in the resonator. In addition, the sensing characteristics of the structure and the influence of its structural parameters are analyzed in detail by investigating the transmission spectra. As a refractive-index sensor, its sensitivity can reach as high as 1150 nm per refractive index unit near the resonance wavelength of 1550 nm, and its sensing resolution can reach 10−6 for a wavelength resolution of 0.01 nm. Furthermore, by employing the relationship between the temperature and the refractive index, the temperature-sensing characteristics of the structure are also discussed. Near the resonance wavelength of 1550 nm, the temperature sensitivity can reach 0.45 nm/°C. The sensor has a compact and simple structure and may find many potential and important applications in optical networks-on-chip and on-chip nanosensors.
Based on a metal-insulator-metal (MIM) waveguide with a side-coupled nanodisk cavity, the sensor using the surface plasmon polaritons (SPPs) refractive index is investigated and studied numerically. The finite-difference time-domain (FDTD) method is used to simulate the performance of the sensor. The numerical simulation result indicates that all the resonance wavelengths in the transmission characteristic of the structure have a linear relationship with the refractive index of the cavity. Furthermore, the sensitivities of the sensor in this paper for the refractive index can be achieved as high as 1320 nm RIU for the mode1, 812.5 nm RIU for the mode2, 600 nm RIU for the mode3, respectively. Besides, the influences of the structural parameters on the transmission characteristic and the sensing characteristic are also studied in detail by the FDTD method. The sensor with compact and simple structure not only can be used to measure the temperature based on the linear relation between the refractive index and temperature, but also has many potential applications in optical networks on chip and On-chip sensor networks.
In the optical communication system, crosstalk noise is always the critical factor affecting the optical signal transmission, especially in networks-on-chip (ONoCs). Based on the model at device, router and network level, this paper proposes the Optimized Crux (OC) router which uses the crossing angle of 60° or 120° instead of the conventional 90° to optimize the Crux optical router. The SNR of the Optimized Crux (OC) router is improved by 2.1dB compared with the Crux on the premise that the size of mesh-based ONoCs is 7×7. By comparing analysis, the results show that to achieve the bit error rate (BER) of 10 −9 for reliable transmissions, the maximum mesh-based ONoCs size has expanded from 4×4 when using the Crossbar optical router to 8×8 when using the OC router.
In this paper, the insertion loss and crosstalk noise of M × N Torus-based optical networks-on-chip (ONoCs) is systematically analyzed, which caused performance degradation. The proposed analysis model can be applied to arbitrary 5×5 routers and Torus-based ONoCs. When traditional non-blocking five-port optical routers used in the original Torus structure, it's suffered lager Bit Error Rate (BER) in a small scale. The router optimization and angle optimization method is used for achieving a better quality of network communication and performance improvement. The numerical results show the signal-to-noise ratio (SNR) of the worst-case transmission link in Torus-based ONoCs with certain size. When the network scale of Torus-based ONoC is 6×6 and the input power is 0 dB, the SNR of Torus-based ONoC using Crux router is 21.66 dB, which is 7.06 dB higher than optimized Crossbar router. With angle optimization further used in router level and network level, the SNR can reach to 23.87 dB. Moreover, we also find that a better SNR can be got with M gradually close to N .
Nonlinear dynamics of a 1550-nm vertical-cavity surface-emitting laser with positive optoelectronic feedback are studied both numerically and experimentally. A mapping of dynamical states is presented in the parameter space of feedback delay time and feedback strength, where different states are identified and shown. A bifurcation diagram of the extrema of output peak series versus the feedback delay time is plotted. Various nonlinear dynamical behaviors, including regular pulsing, quasi-periodic pulsing, and chaotic pulsing, have been numerically and experimentally observed. Both numerical simulation and experimental observation indicate that the laser enters a chaotic pulsing state at certain delay times of the feedback loop through a quasi-periodic route.
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