1. Single-mode lasing in an AlGaInAs/InP dual-port square microresonator
Ke Yang, You-Ling Chen, Ting Wang, Jia-Chen Liu, Ying-Run Fan, Yue-de Yang, Jin-Long Xiao, Yong-Zhen Huang Opt Lett. 2022 Aug 1;47(15):3672-3675. doi: 10.1364/OL.461304.
Mode selection is crucial to achieving stable single-mode lasing in microlasers. Here, we demonstrate experimentally a dual-port square microresonator for single-mode lasing with a side-mode-suppression ratio (SMSR) exceeding 40 dB. By connecting waveguides at two opposite vertices, the quality factor for the antisymmetric mode (ASM) is much higher than that of the symmetric mode (SM), enabling single-mode lasing. Furthermore, far-field interference patterns similar to Young's two-slit interference are observed. This microlaser is capable of providing two optical sources simultaneously for optical signal processing in high-density integrated photonic circuits.
2. Recent advances in mixed-mode chromatographic stationary phases
David Sýkora, Pavel Řezanka, Kamil Záruba, Vladimír Král J Sep Sci. 2019 Jan;42(1):89-129. doi: 10.1002/jssc.201801048. Epub 2018 Dec 11.
Mixed-mode phases have become very popular in the last decade, and the number of new mixed/multi-mode sorbents is growing fast. Unlike single-mode stationary phases, perfectly suited for the separation of the analytes possessing similar physicochemical properties, for instance reversed-phase chromatography for hydrophobic solutes, mixed-mode sorbents providing multimodal interactions can render better separation selectivity for complex mixtures of solutes differing significantly in their physicochemical characteristics. The most frequent modern mixed-mode stationary phases are di/tri-mode sorbents embracing the following interactions, hydrophobic, electrostatic (coulombic), and hydrophilic. According to their structures, it is possible to distinguish silica-based, polymer-based, hybrid, and monolithic mixed-mode stationary phases. Herewith, newly synthesized mixed-mode sorbents developed within the last two and half years are categorized, discussed, and summarized. The main attention is devoted to the description of the synthetic routes and characterization methods applied for the new stationary phases.
3. A review of higher-order mode pass filtering techniques
Prapty Saha, M Salauddin Rasel, Kazi Tanvir Ahmmed Heliyon. 2022 Nov 18;8(11):e11705. doi: 10.1016/j.heliyon.2022.e11705. eCollection 2022 Nov.
Mode Division Multiplexing (MDM) is regarded as a promising technology to overcome the bottleneck of the future demand for high data transmission rates. Multimode fibers are replacing traditional single mode fibers to cope with the increasing bandwidth requirements. MDM works with multiple light modes, and these modes are bound to be coupled with other propagating modes as they pass through guided media. A mode filter removes unwanted modes from the signal received at the receiver after demultiplexing. As a result, designing a highly potential high-order mode pass filter is desired to meet the capacity crunch using the MDM technology. Currently, remarkable research works have been conducted on mode filtering. This paper presents an overview of recent developments in mode filtering techniques along with their designs and fabrication processes. In particular, the mode filter made from different types of materials is reviewed to illustrate the potential of the designs in improving the system performance. Even though commercial success has not been materialized, this work will provide promising prospects in mode filtering techniques for increased flexibility and the choice of different mode filters.
