Ahmad Atieh

• PhD
• VP Optical Systems at Optiwave Systems Inc

Underwater Optical Wireless Communication (UOWC) is emerging as a promising technology for high-speed data transmission in marine environments. This paper introduces a new UOWC system that integrates Optical Code Division Multiple Access (OCDMA) using Identity Shift Column Matrix (ICSM) codes, specifically designed to enhance communication capacity...

Leaky feeders provide seamless and uniform signal coverage in confined spaces like tunnels, mines, and buildings. Their easy scalability and integration with modern systems, like Multiple Input Multiple Output (MIMO), make them ideal for environments requiring reliable and consistent connectivity. However, using optical fiber as a radiating cable h...

The International Renewable Energy Congress (IREC) provides a forum for researchers, academicians, scientists and industrial professionals around the world on recent developments in the fields of renewable energy. The congress consists of keynotes, oral sessions and poster presentations Considered as a catalyst for research works, the IREC publishe...

This paper introduces a novel high-speed Visible Light Communication (VLC) system capable of transmitting data rates of 120 Gbps. The system leverages the multiplexing capabilities of Dual Polarization (DP) and Orbital Angular Momentum (OAM) beams. It incorporates three Laser Diode (LD) sources operating at distinct wavelengths: red (700 nm), green...

Flatness of lasing wavelengths of a multi-wavelength fiber laser (MWFL) is an important design constraint that is considered attractive in various applications of photonics and optical communication systems. In this work, we propose a single-longitudinal mode (SLM) quadruple wavelength C+L-band Erbium-doped fiber laser (EDFL) with high output power...

The Internet of Underwater Things (IoUTs) connects underwater devices to communicate, sense surroundings, and transmit data. Acoustic communication faces bandwidth limitations, making underwater wireless optical communication-free space optics (UWOC-FSO) hybrid systems a promising alternative. However, maintaining sufficient power budget and signal...

This paper demonstrates a five-layer InAs/InP quantum-dash semiconductor optical amplifier (QDash-SOA), which will be integrated into microwave-photonic on-chip devices for millimeter-wave (mmWave) over fibre wireless networking systems. A thorough investigation of the QDash-SOA is conducted regarding its communication performance at different temp...

Spectrally efficient 16 quadrature amplitude modulation‐orthogonal frequency division multiplexing (QAM‐OFDM) system using specifications of commercially available high‐power phosphorous coated LED (PLED) is proposed in this study. To address the challenges of signal attenuation and limited bandwidth, systems integrated with a band pass filter (BPF...

In this paper, a new underwater optical wireless communication (UOWC) system is proposed. It integrates dual-polarization (DP) states with orbital angular momentum (OAM) beams. By leveraging the inherent orthogonality of different OAM modes, the system achieves enhanced signal quality and increased transmission capacity. Each polarization state car...

The safety of SCUBA divers remains at high risk in deep-sea owing to multiple factors such as dangerous surrounding, rely upon technical equipment necessary for life support, decreased underwater navigation, and communication infrastructure. Gradual decrease and increase in water temperature and pressure, respectively corresponding to depth are amo...

We report the design of an all-fiber single-mode polarization maintaining widely tunable Ho-doped master oscillator power amplifier (MOPA) system operating in the wavelength range of 2005-2135 nm based on a pre-amplifier and two power amplification stages. The single clad Ho-doped active fibers in the ring cavity based master oscillator, pre-amplif...

This paper introduces a 400 Gbps free space optics (FSO) system to meet the expected surge in the demand for data traffic. The proposed system is based on using 4-level pulse amplitude modulation (PAM-4) signals in addition to polarization division multiplexing and orbital angular momentum (OAM) multiplexing schemes. To reduce spectrum usage, only...

Optical antennas play a pivotal role in interfacing integrated photonic circuits with free-space systems. Designing antennas for optical phased arrays ideally requires achieving compact antenna apertures, wide radiation angles, and high radiation efficiency all at once, which presents a significant challenge. Here, we experimentally demonstrate a n...

Optical sensors, particularly fiber Bragg grating (FBG) sensors have achieved a fast ingress into the fields of medical diagnostic and vital signs monitoring. Wearable smart textiles equipped with FBG sensors are catching huge research attention in different applications for measurement and monitoring of physiological parameters. In this paper, we...

In optical communication systems, the Q-factor is an important performance metric to evaluate the performance of an optical link. In this paper, a deep learning-based eye diagram analyzer is proposed to estimate the Q-factor. CNN architectures: LeNet, Wide ResNet, and Inception-v4 are used for ON-Off-Keying (OOK) and Pulse Amplitude Modulation (PAM...

Holmium doped fiber amplifiers (HDFAs) have become a focus of researchers since they provide amplification in the very important spectral region around 2 μm wavelength. A major factor resulting in the performance degradation of HDFAs is the inhomogeneous energy transfer within Ho3+ ion-pairs in high-concentration Holmium doped fibers (HDFs), an eff...

This paper introduces a high transmission and secure Underwater Optical Wireless Communication (UOWC) system using Dual Polarization (DP) states, each of them carries three channels assigned with Optical Code Division Multiple Access (OCDMA) code; named, Fixed Right Shift (FRS). A comparison between different transmission powers is performed. The s...

Commercial phosphorous light emitting diodes (PLEDs) have many impairments such as slow response, low bandwidth (BW), and signal attenuation which limit the performance of VLC systems. In our previous work, we proposed an efficient 16 QAM link integrating an optical preamplifier with a PLED. We successfully demonstrated the transmission of 0.5 Gbps...

CA system model for the Line-of-Sight (LoS) Lambertian radiation pattern has been designed with commercially used high power white phosphorous converted white light emitting diode (PLED) of CCTs 2200K, 3000K and 5700 K and three photodiodes of quite different specifications. This system has been successfully tested for the maximum data rate of 300...

In this paper, dual polarization (DP) states and optical code division multiple access (OCDMA) are utilized in an underwater optical wireless communication system (UOWCS). The diagonal permutation shift (DPS) code sequences are assigned to the six OCDMA channels that are utilized in the proposed model. These six channels are divided into two groups...

In this work, the fixed right shift (FRS) code is utilized for the optical code division multiple access (OCDMA) technique in an underwater optical wireless communication (UOWC) system. Additionally, in this system, a 532 nm laser diode (LD) source is employed to generate optical signals. The investigation encompasses an analysis of five distinct J...

We have modelled a free space optical (FSO) channel transmitting data and power at 1550 and 1520 nm, respectively, under various meteorological conditions. Quadratic Phase-Shift Keying is predicted to have the longest viable FSO range.

This paper presents DWDM-based FSO system with 42 channels generated via SOA-Fiber Loop Modulation. System performance is assessed using BER and eye diagrams considering bit rate, and FSO range applicable for high-capacity FSO link.

This paper presents our advancements in silicon integrated photonics for telecommunication and data communication. Our key innovations, including integrated subwavelength gratings, demonstrate promising improvements in device performance and fabrication tolerance.

A new underwater optical wireless communication (UOWC) system utilizing optical code division multiple access (OCDMA) is proposed based on diagonal permutation shift (DPS) code. Different data rates of 2.5 Gb/s, 5 Gb/s, and 10 Gb/s are transmitted simultaneously in this model, where three channels are utilized, each is assigned with a distinct DPS...

We present here a performance comparison of quantum-dash (Qdash) semiconductor amplifiers (SOAs) with three, five, eight, and twelve InAs dash layers grown on InP substrates. Other than the number of Qdash layers, the structures were identical. The eight-layer Qdash SOA gave the highest amplified spontaneous emission power (4.3 dBm) and chip gain (...

Integrated photonics (IP) is an emerging technology in photonics in which optical waveguides (WGs) and devices are fabricated as an integrated structure onto the surface of a flat substrate. IP technology has the great potential for reshaping the high-speed optical communication, sensing, and imaging exploiting the benefits of miniaturization, low...

In this paper, three different modulation formats; namely non return to zero (NRZ), alternate mark inversion (AMI), and carrier compressed return to zero (CSRZ) are used in an underwater optical wireless communication (UOWC) system. A laser diode (LD) source operating at 532 nm is used. A comparison of transmission performance using these modulatio...

The optical transmission window around 2000 nm is getting significant attention for terrestrial and deep-space communication due to lowest absorption. Moreover, it is also being considered as an alternate optical window for spectral expansion beyond C-, Land nd U-bands to resolve the capacity related issues of future optical networks. Holmium-doped...

We proposed a 532 nm wavelength FMCW Lidar varying the RF signal bandwidth for different water types and wavelet pattern attenuation models using the OptiSystem suit for the detectable signals while transmitting low optical power.

Diversity in design is an important factor that enables developers to explore techniques aiming to reduce cost, complexity, and manufacturability. The optical window around 2000 nm is attracting rapid research considerations for the next generation optical networks as a continuation of C-, Land nd U-bands. Optical amplifier is considered to be one...

Türkçe: Demiryolu taşımacılığında trenlerin takibi için farklı tip elektronik algılayıcılar (ray devreleri, dingil sayıcı ve aktif baliz) yaygın olarak kullanılmaktadır. Fakat bu sistemler elektromanyetik alanlardan ve çevresel faktörlerden etkilenebilmektedirler. Fiber optik algılayıcılar (FOS) ise birçok fonksiyonu tek sistem üzerinden sağlayabil...

White LEDs attract researchers for indoor visible light communication systems due to their good modulation characteristics, high efficiency, long lifetime, low cost, high tolerance to humidity, low power consumption, and minimal heat generation. Major challenges need to be resolved for LEDs including signal attenuation, ISI, and limited bandwidth f...

Fiber optic sensing (FOS) has become a well-known technology in response to the rising demands of the railway transportation field despite the abundance of electronic sensing systems in the market. FOS application boasts an all-in-one solution that is both efficient and versatile. In order to enhance the understanding of the capabilities of FOS, th...

This paper proposes a novel 4 ×\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times $$\end{document} 10 Gb/s underwater optical wireless communication system based on...

Mode-locked lasers draw great interest in the laser research field due to their diverse applications and easy achievement of ultra-short and high-intensity optical pulse trains. Actively mode-locked (AML) fiber lasers are more flexible compared to passively mode-locked fiber lasers owing to their ability to control repetition rates and pulse interv...

This paper introduces a novel underwater (UW) optical communication system that utilizes optical code division multiple access transmission technique using the permutation vector code. Three scenarios of water are considered, pure sea (PS), clear ocean (CL), and coastal ocean (CO). The performance is evaluated analytically in terms of bit error rat...

Simultaneous generation of continuous wave (CW) laser and mode-locked pulses employing fiber lasers has not been realized so far to the best of our knowledge. The idea may have various specific applications in the field of photonics and optical communications. Therefore, we propose through numerical simulations a novel method for simultaneous gener...

In this paper, a high-speed short-reach free space optical (FSO) transmission system is proposed for data center interconnect (DCI). This system supports the transmission of 400 Gbps over a single wavelength by employing spatial vertical cavity surface emitting lasers. Space division multiplexing along with polarization division multiplexing of the...

This paper proposes a new cipher image transmission system in free space optics system (FSO). A secure and effective image cryptosystem algorithm based on the Choquet fuzzy integral (CFI) technique and the integer wavelet transform is utilized. Numerical simulations are conducted to examine the efficacy of encrypted images against different attacks...

We propose the design of a free spectral range (FSR) and center wavelength tunable redundant optical comb based on a Sagnac loop mirror (SLM) and bidirectional Mach-Zehnder modulator (BMZM). The optical signal from a continuous wave (CW) laser is split into two parts, one part travels in the clockwise direction and the other part travels in the cou...

A novel 120 Gbps free space optics (FSO) transmission scheme is introduced by combining orbital angular momentum (OAM) multiplexed signals with spectral amplitude coded (SAC)-optical code division multiplexing access (OCDMA) technique. Four OAM beams, each carrying three independent channels with 10 Gbps data rate, are used for increasing the capac...

In the face of rising needs for exchanging different types of information nowadays, a growing demand for higher transmission rates, channel bandwidth, and spectral-efficiency in optical communication links are witnessed. Space division multiplexing (SDM) has garnered significant attention because it adds another dimension to information transmissio...

Broadband amplification in the O+E-band is very desirable nowadays as a way of coping with increasing bandwidth demands. The main issue with doped fiber amplifiers working in this band such as the bismuth-doped fiber amplifier is that they are costly and not widely available. Therefore, a wideband and flat-gain hybrid optical amplifier (HOA) coveri...

Optical wireless communication (OWC) links enable high-speed data transmission between earth stations and satellites. The propagation of optical signals through the atmosphere suffer from atmospheric attenuation and turbulence due to rain, fog, snow, clouds, and wind. The impact of these impairments on propagation of optical signals becomes more pr...

Optical phased arrays (OPAs) are now at the forefront of photonic research as a key beam steering technology for myriad of photonic applications, including in light detection and ranging (LIDAR), communications, and metrology, among others. Integrated OPAs with narrow beam widths and wide-angle steering are in critical need, especially for LIDARs i...

Light detection and ranging systems based on optical phased arrays and integrated silicon photonics have sparked a surge of applications over the recent years. This includes applications in sensing, free-space communications, or autonomous vehicles, to name a few. Herein, we report a design of two-dimensional optical phased arrays, which are arrang...

On-chip optical phased arrays (OPAs) are the enabling technology for diverse applications, ranging from optical interconnects to metrology and light detection and ranging (LIDAR). To meet the required performance demands, OPAs need to achieve a narrow beam width and wide-angle steering, along with efficient sidelobe suppression. A typical OPA confi...

OptiSystem software is a tool that is well suited for conducting numerical simulations for designing fiber lasers. Novel pumping scheme for holmium-doped fiber amplifier (HDFA) using commercially available 980nm and 1480nm laser diodes is proposed using cascaded fiber lasers. The first fiber laser uses erbium-doped fiber to generate a continuous-wa...

A hybrid optical amplifier (HOA) is designed and optimized for the transmission of 40 dense wavelength division multiplexed system (DWDM) channels modulated at 10 Gbps having 25 GHz spacing at the edge of the L and U wavelength bands over more than 250 km. Multi-parameter optimization process is used to achieve the highest gain and best gain flatne...

The optical communication window around 2μm is attracting significant research attention for future optical communication systems as an extension to the C-, L-, and U-bands. One of the research topics in the 2μm region is optical amplifiers. Holmium-doped fiber amplifier (HDFA) is a suitable candidate for amplifying signals in this region. However,...

In this paper, we address the performance optimization of Holmium doped fiber amplifier (HDFA) for optical communications in 2–2.15 μm wavelength range based on a single in-band forward pump source. The performance of the HDFA is analyzed with the help of theoretical simulations by considering an optimized length of Holmium doped fiber (HDF), dopin...

In this paper, we propose and demonstrate through numerical simulations a novel, to the best of our knowledge, widely tunable and switchable multiwavelength erbium-doped fiber laser (EDFL) operating in the 1524–1650 nm wavelength range covering the C-, L-, and U-bands. The EDFL is based on a single ring cavity and a single forward pump source opera...

In this paper, we have designed two multi-core fibres (MCFs) structures with 31 and 37 trench-assisted and air-hole-assisted cores with reduced inter-core crosstalk (XT). The air-hole pairs and triplets are placed between adjacent trench-assisted cores in order to further suppress modal field overlap. The XT analysis of the 31-core design underline...

In this paper, we have designed two multi-core fibres (MCFs) structures with 31 and 37 trench-assisted and air-hole-assisted cores with reduced inter-core crosstalk (XT). The air-hole pairs and triplets are placed between adjacent trench-assisted cores in order to further suppress modal field overlap. The XT analysis of the 31-core design underline...

We report on a two-dimensional optical phased arrays with circular configurations to effectively suppress the grating sidelobes down to 10 dB, while enlarging the steering range to 0.24π and narrowing the angular beamwidths to 0.5°.

We demonstrate a practical wavelength reuse bidirectional analog radio-over-fiber (A-RoF) system served by a single distributed feedback (DFB) laser. Frequency interleaving of downlink and uplink signals is proposed to ameliorate the spectral efficiency and mitigate the interference raised by the bidirectional transmission. Pre-emphasis is exploite...

This paper explores the data carrying capacity enhancement in free space optics (FSO) transmission systems by employing orbital angular momentum (OAM) multiplexing technique. Specifically, simulative investigation of OAM-FSO terrestrial transmission is carried out under varying weather conditions. A net data capacity of 40 Gb/s over free space tran...

Incoherent addition of three monochromatic laser sources is used to create four distinctive power levels to match the profile of standard quaternary pulse amplitude modulation (PAM4). The proposed PAM4 signal generation results in a lower symbol error rate as compared to standard PAM4 systems. This design improves the signal-to-noise ratio as compa...

Numerical simulations for generating and transmitting four Laguerre-Gaussian (LG) modes over 100m of multimode fiber are conducted. Each LG mode is modulated using 10Gbps NRZ signal. Bit error rate (BER) and Q-factor performance metrics showed acceptable system performance as the worst mode has Q-factor of 9.1 and BER of 2.5E-20. Keywords-orbital a...

This presents the architecture, setup and simulated results for a four-channel optical communications system that uses spatial domain multiplexing (SDM) in single core optical fibers using commercially available OptiSystem software. The system components layout, simulated results, eye diagrams and the system bit error ratio (BER) for the individual...

Digital predistortion algorithms are demonstrated for 5G back-bone optical systems employing 64-QAM and 256-QAM advance modulation formats. The performance of the digitally linearized systems is compared experimentally and using simulation with standard coherent transmission systems.

A novel ultra-high capacity free space optics (FSO) link has been developed by incorporating hybrid wavelength divison multiplexing (WDM)-polarization division multiplexing (PDM)-orthogonal frequency division multiplexing (OFDM) techniques with 16-level quadrature amplitude modulation (16-QAM) signals. Coherent detection is employed to enhance the...

We demonstrate a high data rate and low-cost OM4 multimode fiber (MMF) and free-space optics (FSO)-based self-restorable 2 × 100 Gbps per wavelength intra data center interconnect between two pairs of servers. This transmission system is based on two vertical cavity surface-emitting lasers that are directly modulated with PAM-4 data at the rate of...

We demonstrate a high data rate and low-cost OM4 multimode fiber (MMF) and free-space optics (FSO)-based self-restorable 2 × 100 Gbps per wavelength intra data center interconnect between two pairs of servers. This transmission system is based on two vertical cavity surface-emitting lasers that are directly modulated with PAM-4 data at the rate of...

A reconfigurable and application-specific tunable microwave photonic filter having finite impulse response is proposed. The filter exploits the differential mode group delays of linearly polarized modes in a multi-mode fiber to achieve single and multiple high-frequency passband response. The filter taps are realized using a single continuous wave...

In this paper, we propose a cost-efficient single mode fiber-free space optics (SMF-FSO) based hybrid 32x2 Gbps wavelength division multiplexed passive optical network (WDM-PON) employing optical frequency comb (OFC) source and polarization multiplexing. OFC source is realized at optical line termi- nal (OLT) by modulating a single continuous wave...