晶体ZnMgSe：Cr2 +：可调谐红外激光器有源元件的新材料

Spectrally-resolved dielectric function of amorphous and crystalline GeTe nanoparticle thin films

Phase-change materials (PCMs), which are well-established in optical and random-access memories, are increasingly studied for emerging topics such as brain-inspired computing and active photonics. These applications take advantage of the pronounced reflectivity and resistivity changes that accompany the structural transition in PCMs from their amorphous to crystalline state. However, PCMs are typically fabricated as thin films via sputtering, which is costly, requires advanced equipment, and limits the sample and device design. Here, we investigate a simpler and more flexi-ble approach for app…

Blueshift of high-order harmonic generation in crystalline silicon subjected to intense femtosecond near-infrared laser pulse

We present the generation of high order harmonics in crystalline silicon subjected to intense near-infrared 30fs laser pulse. The harmonic spectrum extends from the near infrared to the extreme ultraviolet spectral region. Depending on the pulsed laser intensity, we distinguish two regimes of harmonic generation: (i) perturbative regime: electron-hole pairs born during each half-cycle of the laser pulse via multiphoton and tunnel transitions are accelerated in the laser electric field and gain kinetic energy; the electron-hole pairs then recombine in the ground state by emitting a single high-…

Flexible and tunable silicon photonic circuits on plastic substrates

Flexible microelectronics has shown tremendous promise in a broad spectrum of applications, especially those that cannot be addressed by conventional microelectronics in rigid materials and constructions1-3. These unconventional yet important applications range from flexible consumer electronics to conformal sensor arrays and biomedical devices. A recent successful paradigm shift in implementing flexible electronics is to physically transfer and bond highly integrated devices made in high-quality, crystalline semiconductor materials on to plastic materials4-8. Here we demonstrate a flexible fo…

Photonic Integrated Circuit for Rapidly Tunable Orbital Angular Momentum Generation Using Sb2Se3 Ultra-Low-Loss Phase Change Material

The generation of rapidly tunable Optical Vortex (OV) beams is one of the most demanding research areas of the present era as they possess Orbital Angular Momentum (OAM) with additional degrees of freedom that can be exploited to enhance signal-carrying capacity by using mode division multiplexing and information encoding in optical communication. Particularly, rapidly tunable OAM devices at a fixed wavelength in the telecom band stir extensive interest among researchers for both classical and quantum applications. This article demonstrates the realistic design of a Si-integrated photonic devi…

Widely-tunable, doubly-resonant Raman scattering on diamond in an open microcavity

Raman lasers based on bulk diamond are a valuable resource for generating coherent light in wavelength regimes where no common laser diodes are available. Nevertheless, the widespread use of such lasers is limited by their high threshold power requirements on the order of several Watts. Using on-chip microresonators, a significant reduction of the lasing threshold by more than two orders of magnitude has been shown. However, these resonators lack a continuous tuning mechanism and, mainly due to fabrication limitations, their implementation in the visible remains elusive. Here, we propose a pla…

PCM-net: A refractive index database of chalcogenide phase change materials for tunable nanophotonic device modelling

Recently, chalcogenide glass based phase change materials (PCMs) have shown utility as a tuning material for a range of nanophotonic devices. Owing to their low loss, ultrafast switching speeds and wide waveband operation, PCMs are integrated in an increasing number of next generation tunable components, including integrated photonic switches, metasurface optics and tunable spectral filters. Nonetheless, modelling of PCM-based devices is challenging, both in terms of accurate representation of experimentally-derived material properties in different phase states, and standardization of results …

具有成分依赖响应的Ge_Sb_Te薄膜中的激光诱导光学重构

Laser induced optical reconfiguration in Ge_Sb_Te Films with composition dependent response

研究沉积态结晶GST薄膜中成分与光学响应关系，通过单一CVD过程避免中间相转变，建立了两者直接关联，发现成分梯度影响光学行为，飞秒激光可实现空间选择性调谐，确立其为光子元件平台。

全介电高Q值动态可调透射超表面

All-dielectric high-Q dynamically tunable transmissive metasurfaces

本文提出一种全介电高Q值低损耗主动超表面，通过非晶硅柱谐振器与晶体硅衬底间距设计实现透射共振峰，并利用热光效应在近红外波段实现低至7.3 μs的动态光束切换与转向。

Tunable out-of-plane excitons in 2D single crystal perovskites

Hybrid organic-inorganic perovskites have emerged as very promising materials for photonic applications, thanks to the great synthetic versatility that allows to tune their optical properties. In the two-dimensional (2D) crystalline form, these materials behave as multiple quantum-well heterostructures with stable excitonic resonances up to room temperature. In this work strong light-matter coupling in 2D perovskite single-crystal flakes is observed, and the polarization-dependent exciton-polariton response is used to disclose new excitonic features. For the first time, an out-of-plane compone…

范德瓦尔斯材料的可调谐纳米结构化

Tunable Nanostructuring for van der Waals Materials

针对范德瓦尔斯材料纳米结构化依赖特定晶体、缺乏通用技术的问题，本研究提出飞秒激光烧蚀碎裂的快速通用合成法，可制备50多种前驱体的多形貌纳米晶体，为可调谐vdW纳米结构化提供新范式。