In this paper, we propose O-Star, a scalable optical switching architecture for on-chip many-core systems, employing hybrid mode and wavelength division multiplexing technology. The O-Star uses the Benes topology as the core switching module to realize non-blocking switching. Besides, we design a wavelength and mode allocation module to enable each processor to transmit data in parallel. To quantitatively analyze the minimum hardware cost required, we establish a mathematical model for the different number of processors. As a proof of concept, a 64-core optical switching architecture featuring 8-port Benes topology, 2-mode, and 4-wavelength channels is simulated with single channel 25 Gbps data rate. The O-Star is flexible to scale, both for the number of supported processors and the switching capacity. O-Star holds promise for realizing large-scale optical switching networks to address the incoming challenges of high-performance computing (HPC) systems and data center networks (DCNs).

A terahertz graphene metamaterial decoder, for the first time, is presented which can achieve 2 to 4 decoding function and can be used to detect the content of gaseous tetrahydrofuran in air. The characteristics of the decoder were simulated and optimized by using the finite integration time-domain (FITD) method. The performance of decoding and sensing of the device was investigated. When this device is used as a 2 to 4 decoder, the maximum modulation depth (MD) is 99.60%, the minimum extinction ratio (ER) is 12.63 dB, and the maximum insertion loss (IL) is 0.67 dB. When this device is used as a sensor for tetrahydrofuran detection, the sensitivity (S) can be up to 39.90 nm·L/mmol, along with a quality factor (Q) of 17.1 and a detection limit (DL) as low as 0.31 mmol/L. The results show that the performance of the device in both decoding and sensing functions is relatively well. Simultaneously, due to its insensitivity to the angle of incidence, this device has an anti-interference ability in complex environment. Therefore, this device possesses certain reference significance in decoding, detection, data communication, information anti-counterfeiting and other related fields.

Optical switching has been investigated for a long time, as a possible effective solution to overcome the limitations of power consumption, footprint and scalability in data center networks (DCNs). However, with the increasing DC traffic and narrow channel spacing between wavelengths for optical interconnects, traditional single-mode and multi-waveguide optical switching solutions have encountered bandwidth bottlenecks. To this end, we propose a 2x2 silicon-based on-chip optical switching architecture compatible with hybrid wavelength-and-mode division multiplexing (WDM-MDM), and it is found experimentally that the proposed design increases the bandwidth 8x times with low crosstalk.

A compact dual-parameter optical fiber sensor combining Surface Plasmon Resonance (SPR) and Lossy Mode Resonance (LMR) technologies was proposed for the simultaneous measurement of liquid refractive index (RI) and temperature. The sensor uses an Au film deposited on one side of a D-shaped quartz no-core optical fiber to excite SPR for RI measurement, and a TiO2 film deposited on the other side which coated with PDMS to excite LMR for temperature sensing. Numerical simulation results show that the sensor achieves a maximum sensitivity of 16450 nm/RIU in the RI range of 1.33-1.42, and an average sensitivity of -4.36 nm/°C in the temperature range of 20-100 °C. Furthermore, by further depositing a TiO2 film on the Au film surface to enhance the electric field, the maximum RI sensitivity of the sensor increases to 21650 nm/RIU. This sensor offers a wide measurement range and excellent sensitivity, making it promising for multi-parameter measurement applications.

In this paper, we propose the use of a monolayer graphene metasurface to achieve various excellent functions, such as sensing, slow light, and optical switching through the phenomenon of plasmon-induced transparency (PIT). The designed structure of the metasurface consists of a diamond-shaped cross and a pentagon graphene resonator. We conducted an analysis of the electric field distribution and utilized Lorentz resonance theory to study the PIT window that is generated by the coupling of bright-bright modes. Additionally, by adjusting the Fermi level of graphene, we were able to achieve tunable dual frequency switching modulators. Furthermore, the metasurface also demonstrates exceptional sensing performance, with sensitivity and figure of merit (FOM) reaching values of 3.70 THz/RIU (refractive index unit) and 22.40 RIU-1, respectively. As a result, our numerical findings hold significant guiding significance for the design of outstanding terahertz sensors and photonic devices.

High-capacity wireless-optical switches (WOSUs) have broken through the bottleneck of electrical rate, thus enabling low-latency and high-throughput on-board optical switching (OOS). OOS can effectively relieve the service pressure of ground networks, and it also compensates for the sparse deployment of optical fibers in complex terrains. Compared to widely-used silicon-substrate WOSUs, the passively-programmable metasurface (PMF), fabricated by us, has a golden substrate owning better radiation resistance. Without external electrical excitation for beam steering, our passive manner prolongs the service life of satellites. Moreover, by changing the incident beam polarization without consuming additional power, the data can be transferred between normal and abnormal reflected beams, thus the link backup is naturally performed. Based on multiple PMF chips, we design a novel on-board optical switching matrix (POSM), where the neural network controls chip rotation and movement with high precision. To improve OOS reliability, our enhanced optical switching control module (EOSC) solves POSM reconfiguration, once the matrix port or chip fails due to strong atmospheric drag. Finally, we establish a prototype system with the error-free transmission of ultra-high definition (UHD) video streams for the proof-of-concept, especially for verifying the natural link-backup capability of our PMF. The experimental results show <3 dB insertion loss of normal and abnormal reflected beams in the range of incident angle from 0 $^{\circ }$ to 35 $^{\circ }$ , and other meaningful results demonstrate the potential application of our PMF-cascaded POSM in highly-reliable OOS.