Progress in Quantum Electronics最新文献

We present a review of selective area epitaxy and its history in the evolution of semiconductor lasers, with a focus on its application at the nanoscale level in the development of quantum dot and nanopore lasers. Recent applications will be discussed including applications to integrated photonics and quantum photonics, such as patterned single-photon sources.

Selective area epitaxial (SAE) growth of III-V materials and devices by metalorganic chemical vapor deposition is selectively reviewed to illustrate the concepts employed in this technology and its most relevant applications. Special focus on the use of SAE use for photonic integration, heterogeneous integration of materials relevant to photonic integration, and nanostructure integration is made. Throughout, the pioneering work led by Professor James J. Coleman is used to illustrate the value of using selective growth for various applications.

With the advent of the Internet of Things, energy- and bandwidth-related issues are becoming increasingly prominent in the context of supporting the massive connectivity of various smart devices. To this end, we propose that solar cells with the dual functions of energy harvesting and signal acquisition are critical for alleviating energy-related issues and enabling optical wireless communication (OWC) across the satellite–air–ground–ocean (SAGO) boundaries. Moreover, we present the first comprehensive survey on solar cell-based OWC technology. First, the historical evolution of this technology is summarized, from its beginnings to recent advances, to provide the relative merits of a variety of solar cells for simultaneous energy harvesting and OWC in different application scenarios. Second, the performance metrics, circuit design, and architectural design for energy-autonomous solar cell receivers are provided to help understand the basic principles of this technology. Finally, with a view to its future application to SAGO communication networks, we note the challenges and future trends of research related to this technology in terms of channel characterization, light source development, photodetector development, modulation and multiplexing techniques, and network implementations.

Lasers based on erbium ions using ⁴I_11/2 ​→ ​⁴I_13/2 transition can generate laser radiation in the spectral range from 2.7 ​μm to 3 ​μm. Since the strong absorption peak of water is located at 3 ​μm, there has been an effort to develop a suitable laser source for various medical applications, e.g. dentistry, dermatology, urology, or surgery. Laser radiation from this wavelength range can also be used in spectroscopy, as a pumping source for optical parametric oscillators, or for further mid-infrared conversion.

This paper represents an overview of the erbium-doped active media (e.g. Er:YAG, Er:YAP, Er:GGG, Er:SrF₂, Er:YLF, Er:Y₂O₃, Er:KYW, etc.) for laser radiation generation in the spectral range 2.7–3 ​μm. In the first part of this paper, the particular active media are discussed in detail. On the other hand, the experimental results summarized absorption and emission cross-section spectra together with decay times at upper (⁴I_11/2) and lower (⁴I_13/2) laser levels of all tested Er-doped samples at room temperature. Moreover, laser results in CW and pulsed laser regime with tunability curves, achieved in recent years, are presented, too.

The ultrafast, reversible, nonvolatile and multistimuli responsive phase change of Ge-Sb-Te (GST) alloy makes it an interesting “smart” material. The optical features of GST undergo significant variation when its state changes between amorphous and crystalline, meaning that they are useful for tuning photonic components. A GST phase change material (PCM) can be efficiently triggered by stimuli such as short optical or electrical pulses, providing versatility in high-performance photonic applications and excellent capability to control light. In this review, we study the fundamentals of GST-tuned photonics and systematically summarise the progress in this area. We then introduce current developments in both GST-metal hybrid metamaterials and GST-based dielectric metamaterials, and investigate the strategy of designing reversibly switchable GST-based photonic devices and their advantages. These devices may have a vast array of potential applications in optical memories, switches, data storage, cloaking, photodetectors, modulators, antennas etc. Finally, the prospect of implementing GST PCM in emerging fields within photonics is considered.

Underwater wireless optical communication (UWOC) is an emerging and feasible underwater communication technology and has developed rapidly in recent years. Building a high-performance and practical UWOC system requires comprehensive consideration and optimization design from the device to the system, as well as from the internal modulation to the external environment. This paper provides an overview of the recent developments in UWOC systems, covering aspects about the system transmitters and receivers, advanced modulation formats and underwater channels. Some key technologies to improve transmission capacity of UWOC are classified and summarized to provide guidance for system design. The main challenges and perspectives to achieve a reliable UWOC system are also mentioned. The summary and analysis of these advances and techniques will shed light on the future development of UWOC technology and assist in the construction of the internet of underwater things.

Rectifying antennas are often prensented as a potentiel technological breakthrough for energy harvesting. First theorized in the 1970’s, the downsizing of an antenna coupled with a rectifier has become technologically achievable with the progresses of fabrication techniques such as electron beam or photolithography. However, reaching infrared or visible region of the electromagnetic spectra still entails challenges on the integration of a rectifier operating in the terahertz range. New bottom up approaches are likely to bring a promising solution to this issue. To improve our understanding of the key points of rectifying antennas’ design for the infrared and visible light, and the challenges of device fabrication, this work reviews the progresses of this technology, going back from the first historical RF energy harvesting systems and covering the most innovative trends to this date.

We report on the first watt-level ultrafast laser inscribed Thulium waveguide (WG) lasers. Depressed-index buried channel WGs with a circular cladding (type III) are produced in monoclinic Tm³⁺:KLu(WO₄)₂ crystals. Laser operation is achieved under conventional (³H₆ → ³H₄) and in-band (³H₆ → ³F₄) pumping. In the former case, employing a Raman fiber laser emitting at 1679 ​nm as pump, the continuous-wave Tm channel WG laser generated 1.37 ​W ​at 1915–1923 ​nm with a record-high slope efficiency of 82.7% (with respect to the absorbed pump power), a threshold of only 17 ​mW and a spatially single-mode output with linear polarization. The WG propagation losses were 0.2 ​± ​0.3 ​dB/cm. Passive Q-switching of Tm channel WG lasers is achieved using Cr²⁺:ZnS and Cr²⁺:ZnSe saturable absorbers. With Cr²⁺:ZnS, record-short pulses of 2.6 ns/6.9 ​μJ ​at a repetition rate of 8.0 ​kHz were generated. The developed WGs are promising for compact GHz mode-locked lasers at ~2 ​μm.