To achieve a good balance among the raw modulation bandwidth, the output optical power and the dynamic swing range, three small GaN-based blue LED cells are cascade interconnected on chip to form a 9V HV-LED. A single-stage T-bridge equalizer is proposed to upgrade the -3dB bandwidth and -6dB bandwidth of a VLC/UOWC system based on the HV-LED to be over 700MHz and 900MHz, respectively. To the best of our knowledge, it is the widest bandwidth of a VLC/UOWC system at the similar LED optical power level (120mW). Under the FEC limit of 3.8×10 $^{-3}$ , data rates of 3.4Gb/s over 1.8m free-space transmission and 3Gb/s over 1.2m underwater channel are obtained using 16QAM-OFDM modulation scheme without complex algorithm. The T-bridge equalizer also improves the error free modulation bandwidths up to 450MHz under 16QAM-OFDM, and up to 600MHz under 8QAM-OFDM, respectively. Furthermore, the conjunction of the developed HV-LED and T-bridge equalizer endows the merit of a wide linear region of the modulation response, which will make the communication system be more tolerance to LED's degradation and system fluctuations.

Event-based structured light 3D measurement systems (eSL) overcome intrinsic limitations of frame-based structured light 3D measurement systems (fSL) such as sensor dynamic range, pixel bandwidth, and system optical power. However, most of the existing methods are based on laser scanning, and they are not only limited by the speed of acquisition, but are also very sensitive to noise events. This paper proposes an efficient event-driven fringe projection structured light 3D reconstruction system (eFPSL), aiming for high-precision 3D measurements at increased acquisition speeds. Leveraging a digital light processing fringe projection system, eFPSL enhances the acquisition speed. We further develop a time-frequency analysis algorithm capable of efficiently converting event streams into 2D fringe intensity images with high signal-to-noise ratio and excellent sinusoidality thus mitigating noise event impacts. Moreover, a novel events-count-based shadow mask extraction (eSME) strategy is proposed to eliminate shadow noise. Experimental validations demonstrate eFPSL’s ability to produce higher precision 3D reconstructions, reducing mean absolute error (MAE) by 64% compared to existing eSL methods. In addition, eFPSL impressively safeguards comprehensive 3D results while reducing system power consumption, achieving an 82% reduction in system optical power compared to traditional fSL systems. Most importantly, for high dynamic range (HDR) scenes, eFPSL achieves visual representation and measurement accuracy comparable to eight measurements of fSL systems using only a single measurement, indicating an 87.5% improvement in measurement efficiency. Hence, our experiments confirm eFPSL’s adaptability can extend to HDR scenes involving high-speed motion.

Existing super multi-view (SMV) technologies depend on ultra-high resolution two-dimensional (2D) display panel or large number of 2D display panels to obtain dense sub-viewing-zones for constructing more natural three-dimensional (3D) display by pure spatial-multiplexing. Through gating the spatial-spectrum of each OLED microdisplay, the present work proposes a new SMV technology combining time- and spatial-multiplexing based on planar-aligned OLED microdisplays. The inherent light emission characteristics of OLED, i.e. large divergence angle, guarantees a homogeneous light intensity distribution on the spectrum plane, which is a necessary condition for successful time multiplexing. The developed system bears with low requirements on the number of 2D display panels. The factors influencing the lateral display resolution limit are discussed and the optimum value is deduced. Experimentally, a prototype system with 60 sub-viewing-zones is demonstrated by 12 OLED microdisplays. The horizontal interval between adjacent sub-viewing-zones is 1.6mm.

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By directly flip-chip soldering three mid-power light-emitting diode (LED) chips with periodic micro-via-holes on ceramic substrates, $-3\mathrm{dB}$ modulation bandwidths of 49.9 MHz, 58.8 MHz, and 25 MHz are obtained at the driving current of 170 mA. To the best of our knowledge, these are the reported highest $-3\mathrm{dB}$ bandwidth values for flip-chip power-type LEDs (FC-LEDs) at the low-bias current levels. Moreover, good radiant powers are also achieved: 180.2 mW, 168.8 mW, and 233.8 mW at 150 mA, respectively. With a gold wire-free feature, the fabricated FC-LEDs could offer an opportunity to miniaturize the package volume of a LED module for illumination and free-space high-speed VLC dual-usage applications.

In this paper, we demonstrate that through normal dispenser machines, white light-emitting diodes (wLEDs) with good angular-color uniformity can be obtained with the use of ZnO nanoparticles (NPs). A ΔCCT of 148 K at a correlated color temperature (CCT) level of 6000 K in the angle range of -90° to 90° can be realized by mixing ZnO-QD ₂ NPs (r = 5 nm) at a concentration of 3 wt% with the luminous efficiency loss being less than 5%. If modifying the surface of ZnO by SiO ₂ shell, i.e., ZnO@SiO ₂ , at a concentration of 1 wt%, wLEDs with good comprehensive performances, i.e., angular CCT uniformity, luminous efficiency, and reliabilities are achieved. The ΔCCT is less than 850 K in the angle range of -65° to 65° at a CCT level of around 7000 K. The normalized luminous efficiency is enhanced by a ratio of 8.5%. A SiO ₂ shell of ZnO cores can benefit compatibility between inorganic fillers and organic matrix. Reasons for the existence of an optimized concentration of ZnO@SiO ₂ in silicone are discussed.