A photonics-based radar with generation and de-chirp processing of broadband linear frequency modulated continuous-wave (LFMCW) signal in optical domain is proposed for high-resolution real-time inverse synthetic aperture (ISAR) imaging. In the system, a LFMCW generated by photonic quadrupler based on single integrated electro-optical modulator, echoes reflected from targets are de-chirped to low microwave mixer. The can operate at high large bandwidth, thus achieve an ultra-high range...

Hyunwoo Kim, Jack Hessel, Liwei Jiang, Peter West, Ximing Lu, Youngjae Yu, Pei Zhou, Ronan Bras, Malihe Alikhani, Gunhee Maarten Sap, Yejin Choi. Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing. 2023.

A scheme for photonic generation of linearly chirped microwave waveforms (LCMWs) with a large time-bandwidth product (TBWP) is proposed and demonstrated based on an optically injected semiconductor laser. In the system, laser operated in period-one (P1) oscillation state. After optical-to-electrical conversion, signal can be generated its frequency determined by injection strength. By properly controlling strength, LCMW TBWP generated. The system has simple compact structure. Besides, center...

A photonic approach to generating dual-band linear frequency modulation (LFM) signal is proposed based on optical quadrupling and polarization multiplexing. This achieved by using an integrated multiplexing dual-parallel Mach-Zehnder modulator perform in two orthogonal polarizations independently. After optical-to-electrical conversion, LFM signals different bands can be generated simultaneously. The scheme has a very simple compact structure. Thanks the technique, high-frequency, wideband...

In this paper, a simple scheme for linear frequency-modulated (LFM) waveform generation based on frequency-sweeping optoelectronic oscillator is proposed and demonstrated. The OEO built up with an optically injected semiconductor laser the oscillation frequency can be tuned by adjusting optical injection strength. By applying strength controller in rapid sweeping, LFM microwave generated. When sweep period of output matches round-trip time cavity, signal quality generated significantly...

We propose and experimentally demonstrate an approach to generating reconfigurable radar waveforms based on optically injected semiconductor laser. In the proposed system, laser is operated at period-one oscillation state, in which optical output signal containing a microwave modulation intensity generated. After photo detection, frequency-tunable obtained with its instantaneous frequency determined by injection strength and/or detuning between master slave lasers. Since dynamical behavior...

We propose and numerically demonstrate a high-speed secure key distribution (SKD) based on polarization-keying chaos synchronization in two quantum dot (QD) spin-polarized vertical-cavity surface-emitting lasers (VCSELs) without any external feedback. In this scheme, high-quality can be obtained when the response have same polarization ellipticity. The proposed SKD scheme is benefited from feasible tunability of pump ellipticity, no other complex components are necessary. Moreover, open-loop...

Photonic reservoir computing (RC) is emerging as a competitive candidate for ultra-fast and energy-efficient neuromorphic computing, noted its physical compatibility straightforward training process. However, this widely appreciated form of machine learning typically employs only single hidden layer with feedback loop (FL), which essentially constrains the capability complex task processing poses challenges to integration. Here, we present an integrated deep photonic RC setup based on...

Under proper optical injection, period-one (P1) dynamics of an optically injected semiconductor laser can be excited by undamping the relaxation resonance through Hopf bifurcation. The output intensity would oscillate at a microwave frequency, i.e., P1 frequency. After optical-to-electrical conversion, signal generated with its frequency determined detuning and injection strength. Therefore, it provides convenient way to dynamically control instantaneous manipulating In this work, flexible...

The practical application of chaotic optical communications has been limited by two aspects: the difficulty in concealing time delay - a critical security parameter feedback systems, and significantly enlarging key space without complicating implementation. Here we propose an architecture to break above limits. By introducing frequency-dependent group module with frequency tuning resolution 1 MHz into loop, demonstrate excellent concealment effect, additional huge 1048 can be achieved at...

An approach to generating dual-chirp microwave waveforms (DCMWs) is proposed and experimentally demonstrated. The scheme consists of a typical semiconductor slave laser (SL), which subject dual-beam optical injection from two master lasers with one being positively detuned (${\rm ML}_1$ML1) the other negatively ML}_2$ML2) SL. Under proper conditions, SL operates in so-called Scenario B injection. After optical-to-electrical conversion, dual-frequency signal can be generated its frequencies...

We report on a simple approach of time-delayed reservoir computing (RC) based two-element phased laser array for image identification. Here the with optical feedback and injection is trained according to representative characteristics extracted through histograms oriented gradients. These characteristic vectors are multiplied by random mask signal form input data, which subsequently in reservoir. By optimizing parameters RC, we achieve an identification accuracy 97.44% MNIST dataset 85.46%...

This paper presents a novel microwave photonic (MWP) radar scheme that is capable of optically generating and processing broadband linear frequency-modulated (LFM) signals without using any radio-frequency (RF) sources. In the transmitter, LFM signal generated by controlling period-one (P1) oscillation an injected semiconductor laser. After targets reflection, de-chirping implemented based on dual-drive Mach-Zehnder modulator (DMZM), which followed low-speed analog-to-digital converter (ADC)...

One of the possible noise sources for space-based gravitational wave detector LISA (the Laser Interferometer Space Antenna), associated with its test masses, is that due to spatial variations in surface potential (or patch effect) across surfaces mass and housing. Such will lead force gradients which may result a significant acceleration term. Another source temporal potential, conjunction any ambient dc voltage or net free charge on also produce The ST-7 demonstrator mission designed...

Real-time and high-resolution imaging is demonstrated based on field trial detection of a non-cooperative target using photonics-based inverse synthetic aperture radar (ISAR). By photonic generation de-chirping broadband linear frequency modulation signals, the can achieve high range resolution thanks to large instantaneous bandwidth (8 GHz at K band), as well real-time ISAR low-speed analog-to-digital conversion (25 MSa/s). A small-size unmanned aerial vehicle employed target, realized with...

A frequency tunable short optical pulse generation scheme based on a self-starting optoelectronic oscillator (OEO) with an optically injected semiconductor laser is proposed and investigated. The of pulses repetition rate coarsely tuned from 6.5 to 15 GHz are demonstrated. Phase noise the electrical clock signal OEO below -101 dBc/Hz at 10 kHz within whole tuning range, which leads very small timing jitter generated pulses. Assisted by compression technique in OEO, full-width-at half-maximum...

We propose and numerically demonstrate two reservoir computing (RC) schemes using multiple vertical-cavity surface-emitting lasers (VCSELs) with different external injections, i.e., self-injection mutual injection. The virtual nodes are obtained from the orthogonal polarization modes of VCSELs. evaluate performance our proposed RC systems by chaotic time-series prediction memory capacity (MC). Similar to edge-emitting (EELs), VCSEL-based scheme exhibits better compared a single VCSEL several...

Abstract Ideological divisions in the United States have become increasingly prominent daily communication. Accordingly, there has been much research on political polarization, including many recent efforts that take a computational perspective. By detecting biases text document, one can attempt to discern and describe its polarity. Intuitively, named entities (i.e., nouns phrases act as nouns) hashtags often carry information about views. For example, people who use term “pro-choice” are...

We report on the manipulation of extreme events (EEs) in a slave spin-polarized vertical-cavity surface-emitting laser (spin-VCSEL) subject to chaotic optical injection from master spin-VCSEL. The is free-running but yielding regime with obvious EEs, while originally (i.e., without external injection) operates either continuous-wave (CW), period-one (P1), period-two (P2), or state. systematically investigate influence parameters, i.e., strength and frequency detuning, characteristics EEs....

Optical chaos, especially in the form of parallel temporal/spatial presents a highly efficient approach for high-throughput information processing diverse applications such as optical communication and reinforcement learning. However, despite these advancements, current approaches mainly focus on achieving enhanced single-channel performance or compromised multichannel realization (e.g., sacrificing bandwidth, individual control, system complexity). In this study, an integrated laser array...