Publications by authors named "Xinru Ji"

To realize large-scale production of hydrogen through seawater electrolysis, it is highly crucial to engineer high-activity and robustly stable catalytic materials for oxygen evolution reaction (OER). Here, a facile etching growth strategy based on Ni foam (NF) is employed to fabricate an amorphous/crystalline Ni-Fe based electrode with rich oxygen vacancies as a promising OER electrocatalyst (a/c-NiFeOH@NF). Of note, the introduction of Fe induces the generation of plentiful Ni(Fe)OOH species, which can contribute to the remarkable OER behavior.

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Electro-optical photonic integrated circuits (PICs) based on lithium niobate (LiNbO) have demonstrated the vast capabilities of materials with a high Pockels coefficient. They enable linear and high-speed modulators operating at complementary metal-oxide-semiconductor voltage levels to be used in applications including data-centre communications, high-performance computing and photonic accelerators for AI. However, industrial use of this technology is hindered by the high cost per wafer and the limited wafer size.

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Chip-scale integration is a key enabler for the deployment of photonic technologies. Coherent laser ranging or FMCW LiDAR, a perception technology that benefits from instantaneous velocity and distance detection, eye-safe operation, long-range, and immunity to interference. However, wafer-scale integration of these systems has been challenged by stringent requirements on laser coherence, frequency agility, and the necessity for optical amplifiers.

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Erbium-doped fiber amplifiers revolutionized long-haul optical communications and laser technology. Erbium ions could provide a basis for efficient optical amplification in photonic integrated circuits but their use remains impractical as a result of insufficient output power. We demonstrate a photonic integrated circuit-based erbium amplifier reaching 145 milliwatts of output power and more than 30 decibels of small-signal gain-on par with commercial fiber amplifiers and surpassing state-of-the-art III-V heterogeneously integrated semiconductor amplifiers.

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A photonic dimer composed of two evanescently coupled high- microresonators is a fundamental element of multimode soliton lattices. It has demonstrated a variety of emergent nonlinear phenomena, including supermode soliton generation and soliton hopping. Here, we present another aspect of dissipative soliton generation in coupled resonators, revealing the advantages of this system over conventional single-resonator platforms.

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