Mobile visible light communication (VLC) is key for integrating lighting and communication applications in the 6G era, yet there exists a notable gap in experimental research on mobile VLC. In this study, we introduce a mobile VLC system and investig...
The success of laser communications heavily relies on the stiffness, dynamic properties, static performance, and manufacturability of the U-frame. The U-frame is a fundamental element in satellite-to-ground laser communication telescopes. However, th...
With the development of space laser communication and the planned deployment of satellite Internet constellations, there is a growing demand for microminiature laser communication terminals. To meet the requirements of size, weight and power (SWaP),...
In this study, we have proposed and numerically demonstrated that the bias current of a semiconductor laser cannot be used as a key for optical chaos communication, using external-cavity lasers. This is because the chaotic carrier has a signature of...
Space-based gravitational wave detection uses an equilateral triangular satellite constellation with inter-satellite laser heterodyne interferometry to measure displacement variations caused by gravitational waves. Inter-satellite laser communication...
To investigate the influence of different water quality conditions on the underwater transmission performance of laser communication signals, this paper systematically analyzes the absorption and scattering characteristics of the underwater laser com...
Acquisition, tracking, and pointing (ATP) is a key technology in free space laser communication that has a characteristically high precision. In this paper, we report the acquisition and tracking of low-Earth-orbit satellites using shipborne ATP and...
The New Space movement led to an exponential increase in the number of the smallest satellites in orbit in the last two decades. The number of required communication channels increased with that as well and revealed the limitations of classical radio...
Photonic integrated circuits (PICs) play a leading role in modern information and communications technology. Among the core devices in PICs is the distributed feedback (DFB) multi-wavelength semiconductor laser array. Multi-wavelength semiconductor l...
With the continuous improvement of remote sensing satellite resolution, laser communication technology has gained significant traction. The pointing accuracy of ground-based laser communication terminals is critical for the stability of satellite&nda...
Channel modeling of seawater is essential for understanding the transmission process of underwater laser light and optimizing the system design of underwater wireless laser communication. This study systematically examined the transmission characteri...
Stochastic parallel gradient descent (SPGD) algorithm is one of the most promising methods for effective coherent beam combination. However, the algorithm also has some disadvantages, such as slow convergence speed and local extremum. This paper prop...
This study presents a device for tracking, locating and communicating underwater vehicles as they work near the seabed. The system includes a base station placed on the seabed and a reflective module mounted on a hybrid underwater profiler (HUP). The...
This paper proposes a non-common-view axis alignment method for the alignment requirements of airborne laser communication systems. The system consists of a ground transmitting end and an airborne relay terminal. The ground transmitting end uses a ca...
Inter-satellite laser communication (Is-OWC) is one of the main space optical communication technologies currently studied in various countries. In recent years, a kind of Is-OWC communication terminal without independent beacon light has appeared. S...
The Compressed Sensing (CS) camera can compress images in real time without consuming computing resources. Applying CS theory in the Laser Communication (LC) system can minimize the assumed transmission bandwidth (normally from a satellite to a groun...
To analyze the intensity of atmospheric turbulence in a satellite–ground laser communication link, it is important to consider the effect of increased atmospheric turbulence caused by wind speed. Atmospheric turbulence causes a change in the re...
Satellite laser communication can achieve high-speed, high-precision, and high-security broadband communication without being constrained by the electromagnetic spectrum, which has attracted attention. So, this paper proposes the use of a high-altitu...
This paper proposes a systematic ground experimental method to address the insufficient initial pointing accuracy of optical terminals in free space optical communication (FSO). By utilizing a multi-coordinate system transformation model combined wit...
It is accepted that there exists two kinds of atmospheric turbulence in the Earth’s aerosphere—Kolmogorov and non-Kolmogorov turbulence; therefore, it is important to research their combined impacts on laser-satellite communications. In t...
This paper proposes the use of quasi-stationary aircraft and reconfigurable intelligent surfaces (RIS) to improve the system performance in satellite–terrestrial laser communication downlink. Single-input multiple-output (SIMO) technology is ap...
In this paper, an atmospheric structure constant Cn2 model is proposed for evaluating the channel turbulence degree of atmospheric laser communication. First, we derive a mathematical model for the correlation between the atmospheric coherence length...
Piezoelectric fast steering mirror (PZT FSM) is the core component of the fine tracking system for space laser communication, and its actuator is a piezoelectric ceramic. Consequently, there is a hysteretic nonlinear disturbance throughout the entire...
We propose a compact, beaconless inter-satellite laser communication tracking system based on direct fiber control to address the complexity and resource demands of conventional pointing, acquisition, and tracking (PAT) architectures. Unlike traditio...
To address the challenge of directly applying space laser communication systems to dynamic underwater environments, this paper integrates coordinate transformation matrices with underwater positioning systems, proposing an ultra-short baseline (USBL)...
Aiming at the control challenges of strong nonlinearity, time-varying parameters and multi-channel disturbance coupling in multi-address laser communication networking caused by the common inertial reference of multi-directional mirror strapdown stab...
Visible light communication is an emerging high-speed optical wireless communication technology that can be a candidate to alleviate pressure on conventional radio frequency-based technology. In this paper, for the first time, the advanced modulation...
In this study, a sliding mode control (SMC) algorithm was proposed based on a novel reaching law to solve the nonlinear disturbance problem of a ground-based laser communication turntable. This algorithm is a chatter-free method, in which the coeffic...
In order to optimize space laser communication networking, the 2:1 transmissions for all reflectors on a multi-address transceiver can be removed. However, without the 2:1 transmissions, the reflectors exhibit doubled optical coupling effect in rotat...
The signal-receiving end of acquisition, pointing, and tracking (APT) systems applied to intersatellite laser communication terminals usually uses a fast-steering mirror (FSM) to control the fiber-coupling process, has a complex structural design, an...
Integrated optics, having the unique properties of small size, low loss, high integration, and high scalability, is attracting considerable attention and has found many applications in optical communications, fulfilling the requirements for the ever-...
With the development of communication technology, there is a more urgent demand for enhancing the security of data transmission. In order to improve the security of the traditional chaotic laser communication system, we propose a new scheme by the in...
Gallium nitride (GaN) laser diodes (LDs) are considered for visible light communications (VLC) in free space, underwater, and in plastic optical fibers (POFs). A review of recent results is presented, showing high-frequency operation of AlGaInN laser...
Quantum cascade lasers (QCLs) have emerged as promising candidate sources for free-space communications. High optical power densities, short photon lifetimes, and low internal capacitance are important factors influencing the transmission bandwidth....
We present a key-space-enhanced optical chaos secure communication scheme using a pair of integrated four-section semiconductor lasers as transceivers, which are commonly driven by a DFB laser with bidirectional injection. The transceiver consists of...
In future 6G systems, integrated sensing and communication (ISAC) in the terahertz (THz) band are emerging as a key technology. Photomixing-based approaches offer advantages for the generation and control of THz waves due to their wide bandwidth and...
In this paper, we discuss the design and feasibility of a multifunctional laser instrument capable of precision ranging, time transfer, and wideband communications over interplanetary distances throughout our solar system. To simplify the communicati...
The Japanese National Institute of Information and Communications Technology (NICT) is currently developing a high-performance laser-communication terminal for CubeSats aimed at providing a high-datarate communication solution for LEO satellites requ...
It is well known that the dynamical characteristics of nano-lasers (NLs) have been extensively studied, but there is limited research on chaotic synchronization communication. In this paper, we propose a closed-loop system of mutually coupled NLs. Fi...
The influence of intra-cavity propagation delay in message encoding and decoding using chaotic semiconductor lasers is numerically investigated. A message is encoded at the transmitter laser by a chaos shift keying scheme and is decoded at the receiv...
The utilization of chaotic optical communication, a physical layer security technology, has the potential to enhance the security of optical fiber networks. In this paper, we take knowledge acquired while teaching “A chaotic security system bas...
When a platform carrying a space laser communication system moves through the atmosphere, the relative motion of the turret and the air produces fluctuations in the air density, which affects the beam propagation, and, hence, the laser communication...
Chaotic secure communication schemes encounter a conflict of key space enhancement between the consistency and complexity of chaotic transceivers. In this paper, we propose a monolithically integrated multi-section semiconductor laser (MIMSL), used a...
We propose a scheme for key-space-enhanced chaos secure communication using semiconductor lasers with spectrum-programmable optoelectronic feedback. This feedback consists of multiple parallel optoelectronic feedback loops composed of bandpass filter...
We numerically investigate spin-controlled vertical-cavity surface-emitting lasers (spin-VCSELs) for local oscillators, which are based on an injection locking technique used in coherent optical communications. Under the spin polarization modulation...
Consider a constellation of over a hundred low Earth orbit satellites that aim to capture every point on Earth at least once a day. Clearly, there is a need to download from each satellite a large set of high-quality images on a daily basis. In this...
The radio-over-fiber (RoF) technique has gained a lot of interest recently, as the millimeter-wave signals can be generated and delivered in the optical domain with the advantages of low attenuation, high capacity, and being free from electromagnetic...
This paper examines the growing adoption of laser communication (lasercom) in space missions and payloads for identifying emerging trends and key technology drivers of future optical communications satellite systems. It also presents a comprehensive...
The stand structure of ancient tea tree (Camellia taliensis) communities is critical for maintaining their structural and functional stability. Therefore, this study employed backpack laser scanning (BLS) technology to extract individual tree paramet...
Beyond-5G (B5G) technology plays a pivotal role in the next generation of communication infrastructure to support the future Society 5.0, a concept introduced in the 5th Basic Plan for Science and Technology by the Japanese Cabinet to define the long...
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