Methodology Article
Correlation Between Phase Mask Design and Fiber Bragg Grating Performance
Randriana Heritiana Nambinina Erica*
,
Ando Nirina Andriamanalina
Issue:
Volume 14, Issue 1, March 2026
Pages:
1-8
Received:
15 December 2025
Accepted:
25 December 2025
Published:
19 January 2026
Abstract: Fiber Bragg gratings (FBGs) are regularly spaced patterns written into the core of optical fibers, which reflect certain wavelengths while allowing others to pass. They are widely used in telecommunications, sensing, and photonics. The most common method to create FBGs is the phase mask technique, a reliable and repeatable approach where an ultraviolet (UV) laser is passed through a carefully designed mask, producing an interference pattern that permanently changes the fiber core’s refractive index. The phase mask is a transparent silica plate with etched grooves that diffract the UV light predominantly into the ±1 orders, while suppressing the zeroth order to low levels (typically < 5%), resulting in an interference pattern with a period half that of the mask grating pitch. The spectral performance of an FBG such as its Bragg wavelength, bandwidth, reflectivity, sidelobe suppression, and spectral shape is directly influenced by the physical design parameters of the phase mask. The grating period of the phase mask determines the Bragg wavelength according to the Bragg condition, while the groove depth and duty cycle affect the diffraction efficiency and interference contrast necessary to produce a strong and uniform index modulation. Variations in these parameters can lead to shifts in spectral response or decreased performance, highlighting the importance of precise mask fabrication. This study examines the relationship between phase mask design and FBG optical characteristics by integrating coupled?mode theory and numerical modeling to quantify how mask geometry and fabrication tolerances influence the resulting grating performance. Understanding this relationship enables optimization of phase mask specifications for enhanced grating reflectivity, tailored bandwidth, and reduced sidelobes, which are essential for high?speed optical communication systems and advanced sensor designs. The insights from this work contribute to improved phase mask design strategies, bridging the gap between theoretical modeling and practical implementation of better FBGs.
Abstract: Fiber Bragg gratings (FBGs) are regularly spaced patterns written into the core of optical fibers, which reflect certain wavelengths while allowing others to pass. They are widely used in telecommunications, sensing, and photonics. The most common method to create FBGs is the phase mask technique, a reliable and repeatable approach where an ultravi...
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Research Article
Quantum Kinetic Study of Energy Transport During Ultrashort Laser Interaction with Dense Plasmas
Punit Kumar*
Issue:
Volume 14, Issue 1, March 2026
Pages:
9-20
Received:
18 June 2026
Accepted:
8 July 2026
Published:
23 October 2026
DOI:
10.11648/j.ajop.20261401.12
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Views:
Abstract: The interaction of ultrashort femtosecond laser pulses with dense plasma is a fundamental problem in high-energy-density physics, inertial confinement fusion, advanced particle acceleration, and ultrafast photonics. Under conditions of high electron density and ultrashort time scales, classical kinetic models become inadequate because they neglect quantum phenomena such as wave-particle coherence, quantum diffraction, tunnelling, and nonlocal transport. To address these limitations, this study develops a self-consistent quantum kinetic model based on the coupled Wigner-Maxwell framework. Electron dynamics are described using the Wigner distribution function, while the electromagnetic fields are governed by Maxwell’s equations, enabling simultaneous treatment of quantum transport and wave propagation. Analytical formulations are employed to derive the dispersion relation, damping characteristics, and nonlinear evolution equations governing femtosecond laser pulse propagation in dense plasma. The theoretical predictions are validated through numerical simulations performed with realistic plasma and laser parameters representative of contemporary high-intensity laser experiments. The simulations demonstrate significant quantum modifications to wave dispersion, the emergence of multiple resonance branches, and coherence-driven modulation instabilities that are absent in classical descriptions. These quantum effects substantially influence pulse propagation, energy deposition, and plasma stability, leading to altered laser-plasma interaction dynamics. The results establish that quantum kinetic effects play a decisive role in determining the behaviour of ultrashort laser pulses in dense plasma and therefore must be incorporated into predictive models for high-density plasma systems. The proposed Wigner-Maxwell framework provides a rigorous theoretical foundation for investigating quantum laser-plasma interactions and offers valuable guidance for the interpretation and design of experiments at next-generation high-intensity laser facilities.
Abstract: The interaction of ultrashort femtosecond laser pulses with dense plasma is a fundamental problem in high-energy-density physics, inertial confinement fusion, advanced particle acceleration, and ultrafast photonics. Under conditions of high electron density and ultrashort time scales, classical kinetic models become inadequate because they neglect ...
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