Photonics and Nanostructures-Fundamentals and Applications最新文献

This is an introduction to the special issue “Micro and nano structured mid-IR to Terahertz materials and devices” which aims to cover recent developments in terms of photonics devices operating from the mid-infrared to terahertz wavelength ranges, with possible applications in spectroscopy, sensing, or communications.

Humidity monitoring is paramount in diverse applications, industrial, and medical applications. Surface Plasmon Resonance (SPR) is an optical detection technique capable of sensing various environmental parameters through changes in reflected optical spectra and has garnered significant attention. Typically, SPR sensing employs a single-point detection strategy with the sample at a fixed concentration to achieve optimal sensitivity, limiting its application in dynamic environmental testing. This study proposes an image-based SPR humidity monitoring method, integrating SPR with image processing, enabling dynamic parameter reconstruction, and achieving high responsiveness. Au-PVA is used as a sensing film. To attain the best sensing film thickness, sensing film thicknesses ranging from 94.0 $nm$ to 243.3 $nm$ were tested. Through optimizing film thickness and image data processing, high precision and dynamic responsiveness were achieved. Experimental results demonstrate a response time of 84 $ms$ and an average relative prediction error of 1.57 % for the sensor. Our research holds significant promise for dynamic and accurate humidity detection.

As a typical two-dimensional (2D) ferromagnetic insulator (FI), the Cr₂Si₂Te₆ (CST) has performance ferromagnetic properties. The previous investigation has shown that quantum mechanical simulation can get structure and electronic properties of CST, and the indirect gap value of CST is 0.6 eV by establishing its layered calculation. It implies that the CST is an excellent optical modulator due to larger infrared radiation absorption interval. Based on that, some groups conducted the research of fiber laser based on CST saturable absorber (SA). However, the exploration and application of 2D CST in optics is still in the early stage. In this investigation, the CST was utilized as a SA in an Er-doped fiber laser. The dual-wavelength mode-locked pulse could be observed when the pump power was adjusted from 25 to 140 mW. The CST was applied in Er-doped fiber as SA for generating dual-wavelength mode-locked pulse for the first time. It exhibits performance optical properties that provide a significant reference for exploring the application of 2D materials in ultrafast laser.

Optical technology has seen a revival from the previous decade, in terms of innovations and research, especially relating to optical integrated circuits. Similarly, Photonic Crystals (PCs) are one of the main contenders for the purpose. Therefore, this research work implicates different arrangements of the 3-Dimensional PC units based on the employment of a varying radius PC-cavity and its position i.e., at the beginning and within the middle of the PC-lattice. The effects of these PC-cavities are studied, investigating higher shifting in resonant wavelength, a narrower linewidth around 0.0061 µm and a quality factor of 99.59, comprising of a PC-cavity of radius 0.300 µm using input signal only i.e., coupled into the optical structure using the phenomenon of the Guided-mode-resonances (GMR). The structures are computed using an open-source FDTD platform, employing a stripe-model-based structure utilizing the Periodic Boundary Condition to save time and computational resources and later the PML for the realization of the Finite models. Moreover, the concluded structures based on the position of the PC-cavity, are demonstrated for the design of the all-optical-amplification device, executing a control signal reporting an 8 % of the amplification in the output of the input signal.

We find that the spontaneous and collective emissions have a strong influence on the excitation of two-level absorbers (atoms, molecules) interacting in resonance with the plasmonic mode near the metal nanoparticle. The spontaneous and collective emissions limit the absorption enhancement by the plasmonic mode and make the enhancement possible only with a fast, picosecond population relaxation of the upper absorbing states. Conditions for the maximum of plasmon-enhanced absorption in the presence of spontaneous and collective emissions are found. The nonlinearity in the nanoparticle-absorber interaction and in collective emission causes the bistability in the plasmon-enhanced absorption at high external field intensities and the plasmonic mode excitation.