Tian Jiang

National University of Defense Technology | NUDT · College of OptoElectronic Science and Engineering

Recently, lead halide perovskite quantum dots have been reported with potential for photovoltaic and optoelectronic applications due to their excellent luminescent properties. Herein excitonic photoluminescence (PL) excited by two-photon absorption in perovskite CsPbBr 3 quantum dots (QDs) has been studied at a broad temperature range, from 80 to 3...

Two-dimensional transitional metal dichalcogenides (TMDCs) based lateral heterojunctions have emerged as appealing and intriguing materials for applications in the next generation flexible nanoelectronics. The construction of depletion region near the in-plane interface brings rich opto-electrical dynamics, which is essential for future application...

Optical image encryption has long been an important concept in the fields of photonic network processing and communication. Here, we propose a convolution-like operation-based optical image encryption algorithm exploiting a silicon photonic multiplexing architecture to achieve content security. Particularly, the encryption process is completed in a...

Non‐Hermitian degeneracies, also known as exceptional points (EPs), have presented remarkable singular characteristics such as the degeneracy of eigenvalues and eigenstates and enable limitless opportunities for achieving fascinating phenomena in EP photonic systems. Here, the general theoretical framework and experimental verification of a non‐Her...

Precise and timely collision detection and warning are essential to ensure the safety of autonomous driving. However, existing collision detection systems based on image sensors and radars are prone to misjudgment in adverse environments such as darkness or rain. The lobula giant movement detector (LGMD) neuron found in locusts achieves potential c...

With the explosion of sensory data in the Internet of Things (IoT) era, conventional machine vision systems are becoming increasingly difficult to meet the requirements of high efficiency, low energy consumption, and low latency due to their inherent shortcomings of separate sensing, memory, and computing units. Inspired by the retina and neuromorp...

Optical frequency combs (OFCs) have evolved into one of the most active areas of photonics, underpinning advancements in both fundamental science and commercial contexts. Electro‐optic modulation for OFC generation offers excellent versatility, stability, and phase coherence. With the rapid progress in micro‐nano fabrication techniques, electro‐opt...

Heterostructures composed of two-dimensional van der Waals (vdW) materials allow highly controllable stacking, where interlayer twist angles introduce a continuous degree of freedom to alter the electronic band structures and excitonic physics. Motivated by the discovery of Mott insulating states and superconductivity in magic-angle bilayer graphen...

Analog photonic channelized receivers based on dual optical frequency combs (DOFC) are widely used in microwave photonic wideband signal processing. It uses photonic means to perform narrowband segmentation of the wideband signal spectrum, thus avoiding the tradeoff between speed, bandwidth, and accuracy of ADC. However, many factors such as link n...

A photonic-assisted scheme for spread spectrum communication signals generation is proposed and demonstrated in this article. The spreading sequence and the baseband data codes are modulated on the photonic link by electro-optic modulators, and the spread spectrum process is completed through stream processing on the analog microwave photonic link....

Microcombs have enabled a host of cutting-edge applications from metrology to communications that have garnered significant attention in the last decade. Nevertheless, due to the thermal instability of the microresonator, additional control devices like auxiliary lasers are indispensable for single-soliton generation in some scenarios. Specifically...

Non‐Hermitian degeneracies, also known as exceptional points (EPs), have attracted considerable attention due to their unique physical properties. In particular, metasurfaces related to EPs can open the way to unprecedented devices with functionalities such as unidirectional transmission and ultra‐sensitive sensing. Herein, an active non‐Hermitian...

Controlling the interaction between light and matter at micro- and nano-scale can provide new opportunities for modern optics and optoelectronics. An archetypical example is polariton, a half-light-half-matter quasi particle inheriting simultaneously the robust coherence of light and the strong interaction of matter, which plays an important role i...

We propose and demonstrate a deep learning-assisted photonic approach for measuring the angle-of-arrival (AOA) with high-precision, which is suitable for long- baseline direction finding (DF). A non-uniform linear array with long- baseline is constructed to increase the precision of AOA estimation and to deal with the problem of ambiguity. The syst...

Optical skyrmions have recently attracted growing interest due to their potential applications in deep-subwavelength imaging and nanometrology. While optical skyrmions have been successfully demonstrated using different field vectors, the study of their generation and control, as well as their general correlation with electromagnetic (EM) fields, i...

In the rapidly evolving field of artificial intelligence, integrated photonic computing has emerged as a promising solution to address the growing demand for high-performance computing with increased speed and reduced energy consumption. This study presents a novel silicon photonic cross-scale tensor processing (SiP-CSTP) system on chip, designed t...

With the increase of flight speed, aero-optical effects induced by the turbulent boundary layer near the optical window become increasingly significant. The density field of the supersonic (Mach 3.0) turbulent boundary layer (SPTBL) was measured by nano-tracer-based planar laser scattering technique, and the optical path difference (OPD) was obtain...

Previous studies on photonic neural network have demonstrated that algorithm can inspire hardware design. This study seeks to demonstrate that hardware can also inspire algorithm design. To further exploit the advantages of photonic analog computing, the authors develop hardware and algorithm simultaneously for photonic convolutional neural network...

Optical skyrmions, the optical analogue of topological configurations formed by three-dimensional vector fields covering the whole 4{\pi} solid angle but confined in a two-dimensional (2D) domain, have recently attracted growing interest due to their potential applications in high-density data transfer, storage, and processing. While the optical sk...

Activation of silent synapses is of great significance for the extension of neural plasticity related to learning and memory. Inspired by the activation of silent synapses via receptor insertion in neural synapses, we propose an efficient method for activating artificial synapses through the intercalation of Sn in layered α-MoO3. Sn intercalation i...

Optical neural networks take optical neurons as the cornerstone to achieve complex functions. The coherent optical neuron has become one of the mainstream implementations because it can effectively perform natural and even complex number calculations. However, its state variability and requirement for reliability and effectiveness render traditiona...

High-repetition-rate (up to GHz) femtosecond mode-locked lasers have attracted significant attention in many applications, such as broadband spectroscopy, high-speed optical sampling, and so on. In this paper, the characteristics of dispersion-managed, polarization-maintaining (PM) 1-GHz mode-locked fiber lasers were investigated both experimentall...

The interaction between non-trivial topological states and the magnetic order of intrinsic magnetic topological insulators gives rise to various exotic physical properties,including the quantum anomalous Hall effect and axion insulator, etc. These materials hold great potential for application in low-power topological spintronic devices and topolog...

In this article, a photonic multiformat microwave signal generator with immunity to chromatic dispersion-induced power (CDIP) fading is proposed and demonstrated. A dual-parallel Mach–Zehnder modulator (DPMZM) is driven by a baseband signal to perform a multiformat modulation optical signal. An active demultiplexer based on optical injection lockin...

Retinomorphic Devices In article number 2206816, Yinlong Tan, Tian Jiang, and co-workers report a retinomorphic sensor based on wavelength-dependent bipolar photoconductivity induced by the photocontrolled adsorption and desorption of oxygen molecules on the surface of platinum diselenide. The antagonistic receptive field of the human retina is suc...

Miniaturized ultrafast switchable optical components with high efficiency and broadband response are in high demand to the development of optical imaging, sensing, and high‐speed communication. Sharp Fano‐type resonance switched by active materials is one of the key concepts that underpins the control of light in metaoptics with high sensitivity. H...

An autoencoder-residual (AE-Res) network is designated to assist the linearization of the wideband photonic scanning channelized receiver. It is capable of adaptively suppressing spurious distortions over multiple octaves of signal bandwidth, obviating the need for calculating the multifactorial nonlinear transfer functions. Proof-of-concept experi...

Chromatic adaptation refers to the sensing and preprocessing of the spectral composition of incident light on the retina, and it is important for color image recognition. It is challenging to apply sensing, memory, and processing functions to color images via the same physical process using the complementary metal-oxide-semiconductor technology bec...

Optical frequency comb (OFC) has attracted growing interest in various fields, such as frequency metrology, absorption spectroscopy, and instrumental calibrations. Electro-optic modulation (EOM) is one of the main comb-generating methods with the advantageous features of adjustable repetition frequency, high optical signal-to-noise ratio, and intri...

Microwave photonics scanning channelizer with digital image-reject mixing and linearization is investigated by employing a cascaded distributed feedback semiconductor laser (DFB) operating at stable locking dynamics when subjected to flat optical frequency comb (OFC) injection. The OFC injection locking (OIL) provides a high-quality coherent optica...

A data enhanced iterative few-sample (DEIFS) algorithm is proposed to achieve the accurate and efficient inverse design of multi-shaped 2D chiral metamaterials. Specifically, three categories of 2D diffractive chiral structures with different geometrical parameters, including widths, separation spaces, bridge lengths, and gold lengths are studied u...

Microcombs—generated by coherently pumping nonlinear microresonators—have emerged as a state-of-the-art scheme at the chip scale. Dual-comb spectroscopy (DCS) technology further takes advantage of the miniature system, and has been demonstrated as a powerful tool for real-time and broadband optical sampling of molecular spectra. Here, a novel solit...

Spatiotemporal Lineshape Tailoring In article number 2203680, Tian Jiang and co‐workers demonstrate a novel reconfigurable metasurface supporting a symmetry‐protected bound state in the continuum in the electromagnetic induced transparency window. With active media embedded in the proposed metasurface, spatiotemporal lineshape tailoring with resona...

Integrating metal halide perovskites onto plasmonic nanostructures has recently become a trending method of enabling superior emissive performance of perovskite nanophotonic devices. In this work, we present an in-depth study on the spontaneous emission properties of hybrid systems comprising CsPbBr3 nanocrystals and silver nanostructures. Specific...

Spatiotemporal multiplexing metasurfaces provide an effective approach to ultrafast multidimensional manipulation of terahertz (THz) waves, which is crucial for next-generation communication technology due to the high-capacity and high-speed characteristics. Here, a novel metadevice platform possessing active spatial resonance switching and ultrafa...

Dissipative Kerr solitons (DKSs) with mode-locked pulse trains in high- Q optical microresonators possess low-noise and broadband parallelized comb lines, having already found plentiful cutting-edge applications. However, thermal bistability and thermal noise caused by the high microresonator power and large temperature exchange between microresona...

Alloying is widely applied to tailor properties of 2D materials. Here, we develop a space‐confined chemical vapor deposition (CVD) strategy to homogeneously grow 100 μm‐sized monolayer 1T’‐MoTe2 in batches. Aberration‐corrected annular dark‐field scanning transmission electron microscopy combined with density functional theory calculations is appli...

The bound state in the continuum (BIC) is a unique nonradiating eigenstate that possesses rich physics and has attracted intensive attention in the field of optics and photonics. Actively tailoring BICs in a designable fashion is highly desired for diversified photonic devices. However, to date, most BIC‐assisted works have been limited to showing...

The extraordinary proliferation of digital coding metasurfaces turns the real-time manipulation of electromagnetic (EM) waves into reality and promotes the programmable operation of multifunctional equipment. However, current studies are mainly involved in the modulation of the transmission process, and little attention has been given to the contro...

Searching for ideal materials with strong effective optical nonlinear responses is a long-term task enabling remarkable breakthroughs in contemporary quantum and nonlinear optics. Polaritons, hybridized light-matter quasiparticles, are an appealing candidate to realize such nonlinearities. Here, we explore a class of peculiar polaritons, named plas...

The ability to actively manipulate free-space optical signals by using tunable metasurfaces is extremely appealing for many device applications. However, integrating photoactive semiconductors into terahertz metamaterials still suffers from a limited functionality. The ultrafast switching in picosecond timescale can only be operated at a single fre...

The competition between different spatiotemporal carrier relaxation determines the carrier harvesting in optoelectronic semiconductors, which can be greatly optimized by utilizing the ultrafast spatial expansion of highly energetic carriers before their energy dissipation via carrier–phonon interactions. Here, the excited‐state dynamics in layered...

In this paper, a photonic microwave signals generation scheme for background-free phase-coded (PC) radar pulse with multioctave tuning is experimentally demonstrated. Firstly, an optical frequency comb (OFC) demultiplexing technology based on optical injection locking (OIL) provides a power-equalized coherent optical local oscillator (LO) with ultr...

Infrared and visible image fusion is a beneficial processing task for Unmanned Aerial Vehicle (UAV) surveillance, which can improve visibility by combining the advantages of the infrared camera and the visible light camera. An embedded onboard solution is necessary for UAV-based surveillance missions because it reduces the amount of data that are t...

Although controlled wrinkling is demonstrated to be a powerful tool for micro/nanofabrication, large‐area fabrication of microarchitecture arrays on curved substrates by surface wrinkling still remains challenging. Inspired by the cortical folding, a facile method for transforming graphene oxide (GO) patterns into multiscale microarchitecture array...

We propose an object recognition architecture relying on a neural network algorithm in optical sensors. Precisely, by applying the high-speed and low-power Fourier transform operation in the optical domain, we can transfer the high-cost part of the traditional convolutional neural network algorithm to the sensor side to achieve faster computing spe...

Switchable Metamaterial Devices In article number 2100244, Tian Jiang and co-workers report a novel polarization-coding all-optical metadevice with a temporal dynamic modulation feature. The switching dynamic can be alternated between a quasi-steady state with a recovery time larger than 2 ns and an ultrafast transient state with a recovery time le...

Dual-comb spectrometer is demonstrated as a promising tool in atmospheric composition detection with extremely-high spectral resolution and fast scanning capability. In this paper, an intelligent temporal alignment (ITA) algorithm is proposed into signal processing of a free-running dual-comb spectrometer around 1.5 μm. The signal processing in the...

Experimental investigations of ultrafast electro-optical properties in magnetic materials manifest their great potential for emerging spintronic optoelectronic devices. Here, using time-resolved terahertz emission spectroscopy, we construct a spintronic terahertz emitter consisting of an IrMn3/Ni−Fe heterojunction. A femtosecond spin current pulse...

Recent progress in miniaturized photonic devices has promoted the development of metasurfaces for multidimensional manipulation of optical light fields. One significant example is the polarization multiplexing metadevice, which has earned considerable attention because of its low crosstalk and tremendous polarization-controlled functionalities for...

Developing promoters that can boost the growth quality, efficiency, and robustness of two-dimensional (2D) transition metal dichalcogenides is significant for their industrial applications. Herein a new group (group IIA) of promoters in the periodic table has been disclosed, whose chlorides (especially CaCl2 and SrCl2) exhibit a versatile promoting...

Fundamental researches and explorations based on transition metal dichalcogenides (TMDCs) mainly focus on their monolayer counterparts, where optical densities are limited owing to the atomic monolayer thickness. Photoluminescence (PL) yield in bilayer TMDCs is much suppressed owing to indirect-bandgap properties. Here, optical properties are explo...

Intercalation has been demonstrated to be a powerful tool for tuning the physical and chemical properties of two-dimensional (2D) materials, providing the highest possible doping level and an ideal system to study various electronic states. In this work, we demonstrate that the nonlinear absorption effect of few-layer graphene (about 6–8 layers) is...

The fabrication of conformal nanostructures on microarchitectures is of great significance for diverse applications. Here a facile and universal method was developed for conformal self-assembly of nanospheres on various substrates including convex bumps and concave holes. Hydrophobic microarchitectures could be transferred into superhydrophilic one...

A compact environmentally-stable mode-locked figure-9 fiber laser is reported in this paper. The laser cavity is composed of only two all-polarization-maintaining fiber components, which enjoys a concise and stable structure. As a result, vibration-immune stable fundamental single-pulse mode-locking operation can always be observed. The pulse repet...

Using deep learning, the supervised hyperspectral image (HSI) classification methods are based on the ideal assumption of closed sets, in which all testing classes are defined a priori. However, it is impossible to collect all classes while training in the open set setting where unknown classes can be submitted while testing. Traditional deep neura...

The application of machine learning to the field of ultrafast photonics is becoming more and more extensive. In this paper, for the automatic mode-locked operation in a saturable absorber-based ultrafast fiber laser (UFL), a deep-reinforcement learning algorithm with low latency is proposed and implemented. The algorithm contains two actor neural n...

A scalable multi-task learning (SMTL) model is proposed for the efficient inverse design of low-dimensional heterostructures and the prediction of their optical response. Specifically, several types of nanostructures, including single and periodic graphene-Si heterostructures consisting of n×n graphene squares (n=1∼9), 1D periodic graphene ribbons,...

Deep learning (DL) approaches are demonstrated excellent performance on hyperspectral images (HSIs) classification tasks. Nevertheless, the imbalance between the scant number of available training samples, and the data-driven requirements of DL becomes the major limitation. In this work, we propose a deep convolutional neural network (CNN) with two...

In article number 2006489, Tian Jiang and co-workers propose bifunctional spatiotemporal terahertz metasurfaces, which perform versatile, ultrafast terahertz switching behaviors at continuously alterable resonant states. The incident-angle tunable EIT/LC resonance can be effectively switched-off by means of photon injection.

In article number 2007503, Zhenyu Wang, Jianfeng Wang, Chaoyu Chen, and co‐workers develop a practical strategy to construct moiré Dirac cones around the Brillouin zone center by folding graphene Dirac cones in monolayer In2Se3/bilayer graphene heterostructures. The Fermi velocity of the moiré Dirac cones is reduced by ≈23%, and the reshaped Dirac...

Metasurface plays a key role in various terahertz metadevices, while the designed terahertz metasurface still lacks flexibility and variety. On the other hand, inverse design has drawn a plenty of attentions due to its flexibility and robustness in the application of photonics. This provides an excellent opportunity for metasurface design as well a...

Advances in tunable metamaterials/metasurfaces facilitates their utilization in novel optical components, and lead to many breakthroughs in light tailoring by giving birth to diverse spatiotemporal dynamics. In the ascendant field of terahertz (THz) photonics, the ultrafast modulation is the fundamental process of technological advancements in high...

Although excellent performance such as high efficiency and stability have been achieved in quantum dot (QD)‐based light‐emitting diodes (QLEDs) possessing an organic/inorganic hybrid device structure, the highly expected all‐inorganic QLEDs remain at the bottleneck stage in recent years, resulting from the luminance quenching of QDs caused by inorg...

Emergent phenomena such as unconventional superconductivity, Mott‐like insulators, and the peculiar quantum Hall effect in graphene‐based heterostructures are proposed to stem from the superlattice‐induced renormalization of (moiré) Dirac fermions at the graphene Brillouin zone corners. Understanding the corresponding band structure commonly demand...

Emergent phenomena such as unconventional superconductivity, Mott-like insulators, and the peculiar quantum Hall effect in graphenebased heterostructures are proposed to stem from the superlattice-induced renormalization of (moiré) Dirac fermions at the graphene Brillouin zone corners. Understanding the corresponding band structure commonly demands...

Mg3Bi2 has been proved to be a semimetal with topological surface states (referred to as a topological semimetal, TSM) in the presence of spin-orbit coupling (SOC), and predicted to be a type-II nodal line semimetal (NSM) in the absence of SOC. It is possible to tune the effective SOC in Mg3Bi2 by substituting the heavy Bi atom with lighter atoms,...

In article number 2000456, Tian Jiang and co‐workers propose a novel spatiotemporal terahertz meta‐device, which equips temporally ultrafast all‐optical terahertz switching with spatially selective nonvolatile resonances. By leveraging both degrees of freedom in space and time domains, this work directly promotes the emergence of highly functional...

Recently, hyperspectral imaging (HSI) supervised classification has achieved an astonishing performance by using deep learning. However, most of them take the ideal assumption of ‘closed set’, where all testing classes have been known during training. In fact, in the real world, new classes unseen in training may appear during testing. Obviously, t...

Optoelectronic terahertz switching achieved by dynamically tuning metamaterials is viewed as a major breakthrough in promoting the advancement of terahertz technology. However, the main thrust toward the development of ultrafast switchable components and optical logic operations is still in a catch‐up stage for progressively increasing information...

A model-agnostic data enhancement (MADE) algorithm is proposed to comprehensively investigate the circular dichroism (CD) properties in the higher-order diffracted patterns of two-dimensional (2D) chiral metamaterials possessing different parameters. A remarkable feature of MADE algorithm is that it leverages substantially less data from a target p...