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Electro–optic modulator is a key component for on-chip optical signal processing. An electro–optic phase modulator based on multilayer graphene embedded in silicon nitride waveguide is demonstrated to fulfill low-power operation. Finite element method is adopted to investigate the interaction enhancement between the graphene flake and the optical mode. The impact of multilayer graphene on the performance of phase modulator is studied comprehensively. Simulation results show that the modulation efficiency improves with the increment of graphene layer number, as well as the modulation length. The 3-dB bandwidth of around 48 GHz is independent of graphene layer number and length. Compared to modulator with two- or four-layer graphene, the six-layer graphene/silicon nitride waveguide modulator can realize π phase shift at a low-power consumption of 14 fJ/bit when the modulation length is 240 μm.

We propose a novel and efficient multi-functional optical fiber sensor system based on a dense wavelength division multiplexer (DWDM). This system consists of an optical fiber temperature sensor, an optical fiber strain sensor, and a 48-channel DWDM. This system can monitor temperature and strain changes at the same time. The ranges of these two sensors are from −20 °C to 100 °C and from −1000 μ ε to 2000 μ ε , respectively. The sensitivities of the temperature sensor and strain sensor are 0.03572 nm/°C and 0.03808 nm/N, respectively. With the aid of a broadband source and spectrometer, different kinds and ranges of parameters in the environment can be monitored by using suitable sensors.

In this work, long-period waveguide grating-based tunable wavelength filters using organic–inorganic grafting poly(methyl methacrylate) (PMMA) materials are designed and fabricated by metal-cladding directly defined technique. The thermal stabilities and optical properties of the organic–inorganic grafting PMMA core materials are analyzed. Structures and performance parameters of the waveguide gratings and self-electrode heaters are designed and simulated. The contrast of the filter is about 15 dB and the resonant wavelength can be tuned by different electric powers applied to the metal-cladding self-electrode heaters. The temperature sensitivity is 3.5 nm/°C and the switching time is about 1 ms. The technique is very suitable for realizing the optoelectronic integrated wavelength-division-multiplexing systems.