Article
Optics
Nivedita Nair, Sanmukh Kaur, Hardeep Singh
Summary: This study presents the design and implementation of all-optical shift registers that can transfer input information bits in serial or parallel configuration based on clock signal transitions. Utilizing cross-coupled semiconductor optical amplifiers and an optical NOT gate, the shift registers were tested at an operational speed of 100 Gb/s, showing reduced complexity and footprint ideal for photonic integration.
Article
Engineering, Electrical & Electronic
A. F. Qasrawi, Rana B. Daragme
Summary: In this study, thin films of selenium oxide were coated onto transparent indium substrates under vacuum condition, and their structural, optical, and electrical characteristics were analyzed. The results showed that continuous film formation and induced crystallization of selenium oxide were achieved using indium substrates, resulting in enhanced light absorbability and optical conductivity. Additionally, a new second band gap was formed at the ultrathin interface of indium/selenium oxide. Moreover, the study demonstrated the potential applications of selenium oxide in nonlinear optics and thin film transistor fabrication.
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Li Liu, Shasha Liao
Summary: This study proposes and experimentally demonstrates an optimized notch microwave photonic filter based on silicon material, which features sub-gigahertz narrowband, ultra-high rejection ratio, and tunable bandwidth. The experimental results show that the filter has a narrow 3dB bandwidth of 185 MHz, rejection ratio beyond 70 dB, and a tuning range of 3dB bandwidth from 185 MHz to 1.263 GHz.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Henan Zeng, Ruoming Li, Wangzhe Li
Summary: A novel photonic frequency up/down-converting interface (FCI) is proposed in this paper, which can up-convert an intermediate frequency (IF) signal to a radio frequency (RF) signal and simultaneously down-convert a RF signal to a low IF signal. The FCI is tested in a deramp-on-receive linearly frequency modulated (LFM) continuous wave (CW) radar system, and it shows the capability of accurately transmitting and receiving LFM signals and generating coherent deramp output signals that result in a clear image of point-targets with high resolution. This research is significant in improving the performance of radar systems.
Article
Engineering, Electrical & Electronic
Hussein E. Kotb, Yasser M. Sabry, Mohab S. Abdallah, Haitham Omran
Summary: This work introduces a MEMS-SOA active interferometer for MPF as a tunable sliced source and auto-equalizer, improving passband attenuation uniformity and achieving a high tuning resolution.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2021)
Article
Multidisciplinary Sciences
Mohammad Alibakhshikenari, Bal S. Virdee, Shahram Salekzamankhani, Sonia Aissa, Chan H. See, Navneet Soin, Sam J. Fishlock, Ayman A. Althuwayb, Raed Abd-Alhameed, Isabelle Huynen, James A. McLaughlin, Francisco Falcone, Ernesto Limiti
Summary: This research demonstrates the effectiveness of using SIW technology to enhance the performance of antenna arrays for sub-THz integrated circuit applications, achieving significant improvements in isolation, radiation gain, and efficiency. The proposed approach shows the viability of developing antenna arrays for sub-THz integrated circuits.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Analytical
Benish Kanwal, Ammar Armghan, Salman Ghafoor, Ahmad Atieh, Muhammad Sajid, Tasleem Kausar, Jawad Mirza, Yun Lu
Summary: This paper proposes and demonstrates a wideband and flat-gain hybrid optical amplifier (HOA) based on a parallel combination of a praseodymium-doped fiber amplifier (PDFA) and a semiconductor optical amplifier (SOA). The HOA achieves flat gain characteristics in the O+E band and evaluates the transmission performance as a pre-amplifier for different data rates using bit-error rate (BER) analysis.
Article
Physics, Applied
Juan Arturo Alanis, Joshua Robertson, Matej Hejda, Antonio Hurtado
Summary: This paper presents a high-speed and tunable photonic synaptic element based on VCSOA, allowing full weight tunability of sub-ns input light pulses by varying the bias current. The VCSOA-based synapse offers gain and dynamical weight tuning at high-speed with up to 11.6-bit precision, making it a promising solution for future neuromorphic photonic systems.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
Li Wang, Tsung-Tse Lin, Ke Wang, Hideki Hirayama
Summary: This study investigates the impact of parasitic absorption in the narrow module architecture with only two quantum wells, in the context of terahertz quantum cascade lasers utilizing the nonalignment injection scheme via direct-phonon resonance. The optical gain is found to be limited to small (or negative) values even at low temperatures. To address this issue, a strategy of suppressing parasitic absorption by increasing the injection energy is adopted, resulting in successful lasing at 194 K.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Multidisciplinary
Manal M. Alkhamisi, A. F. Qasrawi, Hazem K. Khanfar
Summary: Amorphous tungsten oxide thin films with a thickness of 300 nm were coated onto semitransparent Pb films using thermal evaporation under a vacuum pressure of 10(-5) mbar. Optical investigations revealed that Pb nanosheets increase light absorbability in the visible and infrared ranges without affecting the energy band gap. The optical conductivity and terahertz cutoff frequency spectra of the Pb/WO3 optical filters showed that the cutoff frequency in the visible range remains constant regardless of light signal energy, suggesting the potential for filtering non-monochromatic light signals. Moreover, the Pb/WO3/Au devices demonstrated the ability to function as low pass and band stop filters in the microwave frequency domain, with a cutoff frequency of approximately 9 GHz, making it suitable for 5G mobile technology. Overall, this study highlights the use of tungsten oxide coating on semitransparent Pb substrates for gigahertz/terahertz band filters in communication technology.
Article
Engineering, Electrical & Electronic
A. F. Qasrawi, Shatha N. Abu Alrub, Rana B. Daragme
Summary: In this study, tungsten oxide thin films with excess oxygen were investigated as optical resonators for gigahertz/terahertz applications. The amorphous WO3 films prepared by thermal evaporation technique exhibited high transparency and showed potential applications in the infrared, visible, and ultraviolet ranges. The wide tunability of these films makes them promising for optical communications.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Weihao Li, Mingming Zhang, Yifan Zeng, Yizhao Chen, Junda Chen, Yuqi Li, Ming Tang
Summary: In this work, we propose a reach-extended, cost-efficient SHC-BiDi scheme suitable for metro-DCI applications. By utilizing bidirectionally operated SOAs, linear signal amplification and remote LO regeneration are achieved, enabling successful 400 G dual-polarization 16QAM transmissions.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Mohd Farman Ali, Zaid Jawed, Vinamra Raj, Gaurav Varshney
Summary: A tunable filtering THz antenna is designed and numerically studied with a slotted monopole radiator and defected ground structure. It operates with a wideband response and an impedance bandwidth in the range of 3.80-11.98 THz for S-11 <=-10 dB. By varying the chemical potential, the antenna response can achieve tunability in the frequency and bandwidth of the filtered band in the range of 5.05-6.69 THz with graphene material. Furthermore, the antenna exhibits a radiation efficiency of more than 90% and a gain peak value of 6.6 dBi in the passband.
Article
Optics
Pei-Jung Wu, Wei-Cheng Tsai, Chan-Shan Yang
Summary: In this study, an electrically tunable multi-band terahertz (THz) metamaterial filter based on graphene and multiple-square-loop structures was designed. The structure consists of multiple metal square loops of different sizes, which correspond to different THz frequencies, achieving the expected efficacy of a multi-band wave filter. By sweeping external voltages, the capability of the high-sensitivity THz filter can be modulated from single-band to multi-band filtering by changing graphene's Fermi levels. This hybrid THz wave filter study shows promise for the development of selecting channels in THz and 6G communications.
Article
Materials Science, Multidisciplinary
Meisam Esfandiyari, Ali Lalbakhsh, Saughar Jarchi, Mohsen Ghaffari-Miab, Hamideh Noori Mahtaj, Roy B. V. B. Simorangkir
Summary: This paper presents a novel tunable graphene-based bandstop filter/antenna-sensor. The structure combines filtering and high-gain radiation performance. The conductivity of graphene and its structural parameters are studied to optimize the component performance.
MATERIALS & DESIGN
(2022)
