Publications by authors named "H F Chang"

Deep-ultraviolet (DUV) light is essential for applications including fabrication, molecular research, and biomedical imaging. Compact metalenses have the potential to drive further innovation in these fields, provided they utilize a material platform that is cost-effective, durable, and scalable. In this work, we present aluminum nitride (AlN) metalenses as an efficient solution for DUV applications.

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Due to mode coupling, a high signal-to-noise ratio (SNR) is required in orbital angular momentum (OAM) modular division multiplexing (MDM) systems to improve transmission performance. In this paper, a cascade delta-sigma modulation (CDSM) scheme is proposed for OAM-MDM intensity modulation and direct detection (IM/DD) transmission. Different from the traditional DSM (TDSM) scheme, the scheme is divided into signal modulation and in-band noise modulation, in which the in-band noise modulation is used to further decrease the quantization noise generated in the signal modulation.

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This paper presents a synthetic holographic stereogram printing approach that integrates neural radiance fields (NeRF) with the effective perspective images segmentation and mosaicking (EPISM) method. Sparse perspectives of a 3D scene are captured through random sampling and used to train a NeRF model with multi-resolution hash encoding, enabling rapid construction of an implicit scene representation. The EPISM method calculates the camera pose parameters needed for parallax images, which are rendered through the trained neural network.

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Orbital angular momentum (OAM) multiplexing is emerging as a critical technique for achieving high data capacity in underwater wireless optical communications (UWOC). Nonetheless, wavefront distortions induced by underwater turbulence compromise the orthogonality of OAM modes. In this paper, we introduce a physics-driven untrained learning approach for adaptive optics that operates independently of extensive amplitude datasets.

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Background/purpose: Revascularization procedures are used over apexification to treat teeth with necrotic pulp tissues and incomplete root formation. Clinically, inducing proliferation, migration, matrix deposition, and differentiation of stem cells from apical papilla (SCAPs) are critical for pulp regeneration. The study aimed to elucidate the impact of bone morphogenetic protein-4 (BMP-4) on plasminogen activation molecules and the osteogenic/odontogenic differentiation of SCAPs, as well as understand the related signaling mechanisms.

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