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15 September 2022 in Journal of Lightwave Technology
We put forward and present a demonstration of an actively controlled optical beam steering optical wireless communication (OWC) system based on an integrated actively steerable optical phased array (OPA). We theoretically and experimentally analyze the emitted optical beam full-width-half-maximum (FWHM) divergence angle and field-of-view (FOV) of the proposed integrated actively steerable OPA. Experimental results show that the beam steering can be achieved over a range of 17° with a minimum optical beam FWHM divergence angle of 1.49°. Besides, the integrated OPA chip design, beam forming optimization, packaging, as well as temperature stabilization are also discussed. Genetic Algorithm (GA) is utilized to optimize the applied voltages for the 30 phase shifters to produce low-divergence optical beams in different directions. A proof-of-concept bit-error-rate (BER) measurement using 10 Gbit/s on-off-keying (OOK) signal is also carried out, and the beam steered optical signal satisfying the pre-forward error correction BER limit (pre-FEC BER = 3.8 × 10 −3 ) is achieved.
We propose and demonstrate a tunable and stable single-longitudinal-mode (SLM) erbium fiber laser with a passive triple-ring cavity structure in S-band operation. The proposed laser is fundamentally structured by using three different lengths of ring cavities, which serve as the mode filters. When a mode-restricting intracavity fiber Fabry-Perot tunable filter (FFP-TF) is combined, the proposed resonator can guarantee a tunable and stable SLM laser oscillation. Moreover, the performances of the output power, wavelength stability, tuning range, and side-mode suppression ratio (SMSR) are studied.
Visible light communication (VLC) can provide a dedicated, secure, and high data rate wireless transmission link. It has gained considerable attentions recently, and is considered as one of the promising technologies for beyond 5G mobile and wireless communications. In this work, we demonstrate a VLC system with a recorded data rate of 40.665 Gbit/s using tricolor red, green and blue (RGB) laser diodes (LDs) and polarization multiplexing. 2 m free-space transmission distance is achieved. The implementation of bit-loading, power-loading, and polarization multiplexing are discussed. Experimental bit-error-ratio (BER) results show that each of the 6 polarization and wavelength de-multiplexed channels can achieve the forward-error-correction (FEC) requirement.
We put forward and demonstrate a angle-of-arrival (AOA) based visible-light-positioning (VLP) system using quadrant-solar-cell (QSC) and third-order ridge regression machine learning (RRML) to improve the positioning accuracy.
To increase the traffic rate in phosphor-LED visible light communication (VLC), a multi-band orthogonal frequency division multiplexed (OFDM) modulation is first proposed and demonstrated. In the measurement, we do not utilize optical blue filter to increase modulation bandwidth of phosphor-LED in the VLC system. In this proposed scheme, different bands of OFDM signals are applied to different LED chips in a LED lamp, this can avoid the power fading and nonlinearity issue by applying the same OFDM signal to all the LED chips in a LED lamp. Here, the maximum increase percentages of traffic rates are 41.1%, 17.8% and 17.8% under received illuminations of 200, 500 and 1000 Lux, respectively, when the proposed three-band OFDM modulation is used in the VLC system. In addition, the analysis and verification by experiments are also performed.