ABSTRACT
A 16 Gb/s four-level pulse amplitude modulation (PAM4) underwater wireless optical communication (UWOC) system based on 488-nm laser diode (LD) with light injection and optoelectronic feedback techniques is proposed and successfully demonstrated. Experimental results show that such a 1.8-GHz 488-nm blue light LD with light injection and optoelectronic feedback techniques is enough forceful for a 16 Gb/s PAM4 signal underwater link. To the authors' knowledge, this study is the first to successfully adopt a 488-nm LD transmitter with light injection and optoelectronic feedback techniques in a PAM4 UWOC system. By adopting a 488-nm LD transmitter with light injection and optoelectronic feedback techniques, good bit error rate performance (offline processed by Matlab) and clear eye diagrams (measured in real-time) are achieved over a 10-m underwater link. The proposed system has the potential to play a vital role in the future UWOC infrastructure by effectively providing high transmission rate (16 Gb/s) and long underwater transmission distance (10 m).
ABSTRACT
A bidirectional fiber-invisible laser light communication (IVLLC) and fiber-wireless convergence system with two orthogonally polarized optical sidebands for hybrid cable television (CATV)/millimeter-wave (MMW)/baseband (BB) signal transmission is proposed and experimentally demonstrated. Two optical sidebands generated by a 60-GHz MMW signal are orthogonally polarized and separated into different polarizations. These orthogonally polarized optical sidebands are delivered over a 40-km single-mode fiber (SMF) transport to effectually reduce the fiber dispersion induced by a 40-km SMF transmission and the distortion caused by the parallel polarized optical sidebands. To the best of our knowledge, this work is the first to adopt two orthogonally polarized optical sidebands in a bidirectional fiber-IVLLC and fiber-wireless convergence system to reduce fiber dispersion and distortion effectually. Good carrier-to-noise ratio, composite second order, composite triple beat, and bit error rate (BER) are achieved for downlink transmission at a 40-km SMF operation and a 100-m free-space optical (FSO) link/3-m RF wireless transmission. For up-link transmission, good BER performance is acquired over a 40-km SMF transport and a 100-m FSO link. The approach presented in this work signifies the advancements in the convergence of SMF-based backbone and optical/RF wireless-based feeder.
ABSTRACT
A 64 Gb/s four-level pulse amplitude modulation (PAM4) vertical-cavity surface-emitting laser (VCSEL)-based free-space optical (FSO) link with an external light injection scheme is proposed and successfully demonstrated. Experimental results show that the 11.2 GHz VCSEL with an external light injection scheme is sufficiently powerful for 64 Gb/s PAM4 FSO links. This study is the first one that adopts a 1550-nm VCSEL transmitter with an external light injection scheme in a 64 Gb/s PAM4 FSO link. The link performances of the proposed PAM4 VCSEL-based FSO links have been analyzed in real-time in terms of eye diagrams and offline processed by Matlab in terms of bit error rate (BER) performances. Good BER performance and clear eye diagrams are acquired over a 100-m free-space link. Such a proposed 64 Gb/s PAM4 VCSEL-based FSO link with an external light injection scheme is a promising one for providing high transmission rate and long transmission distance.
ABSTRACT
A 45 Gb/s four-level pulse amplitude modulation (PAM4) transmission based on an 850 nm/7.4 GHz vertical cavity surface emitting laser (VCSEL) with light injection and optoelectronic feedback techniques is proposed. Experimental results show that such an 850 nm/7.4 GHz VCSEL with light injection and optoelectronic feedback techniques is powerful enough for a 45 Gb/s PAM4 signal transmission. To the best of our knowledge, this Letter is the first to adopt a VCSEL transmitter with light injection and optoelectronic feedback techniques in a 45 Gb/s PAM4 transmission system. Good bit error rate performance and three independent clear eye diagrams are achieved over a 200-m OM4 multimode fiber transport. This proposed 45 Gb/s PAM4 VCSEL-based transmission system has great potential for providing effective bandwidth in short-reach optical data communications.
ABSTRACT
A bidirectional fiber-wireless and fiber-invisible laser light communication (IVLLC) integrated system that employs polarization-orthogonal modulation scheme for hybrid cable television (CATV)/microwave (MW)/millimeter-wave (MMW)/baseband (BB) signal transmission is proposed and demonstrated. To our knowledge, it is the first one that adopts a polarization-orthogonal modulation scheme in a bidirectional fiber-wireless and fiber-IVLLC integrated system with hybrid CATV/MW/MMW/BB signal. For downlink transmission, carrier-to-noise ratio (CNR), composite second-order (CSO), composite triple-beat (CTB), and bit error rate (BER) perform well over 40-km single-mode fiber (SMF) and 10-m RF/50-m optical wireless transport scenarios. For uplink transmission, good BER performance is obtained over 40-km SMF and 50-m optical wireless transport scenario. Such a bidirectional fiber-wireless and fiber-IVLLC integrated system for hybrid CATV/MW/MMW/BB signal transmission will be an attractive alternative for providing broadband integrated services, including CATV, Internet, and telecommunication services. It is shown to be a prominent one to present the advancements for the convergence of fiber backbone and RF/optical wireless feeder.
ABSTRACT
UNLABELLED: In this study, gaseous benzene, toluene, ethylbenzene, and o-xylene (BTEX) were extracted by passive needle trap samplers (NTS) using divinylbenzene (DVB) particles (mesh sizes 60-80, 80-100, and 100-120, respectively) as packed sorbents. An aspirating pump measured sampling flow rates of NTS, and the relations between BTEX mass and sampling flow rates were sufficient to maintain the extraction performance of these self-designed DVB-NTS. Furthermore, this investigation compared the extraction efficiency of NTS with that of the 100-microm polydimethylsiloxane solid-phase microextration (PDMS SPME) fiber when applied to sample heating products from electric-vaporization anti-mosquito mats, and the experimental results indicated that NTS effectiveness increased with decreasing adsorbent particle diameter. Substantially less mass of gaseous BTEX was extracted using 100-microm PDMS SPME fiber than with NTS of 100-120 mesh DVB for 60-min TWA sampling of anti-mosquito mats. The 100-120 mesh DVB-NTS primarily adsorbed 4.2 ng acetone, 13.3 ng dichloromethane, and 4.5-25.3 ng C10-C12 alkanes. IMPLICATIONS: The needle trap sampler (NTS) has been evaluated to be a device for sampling heating products from electric-vaporization anti-mosquito mats. Based on the experimental results, this investigation assessed NTS as suitable for occupational and environmental health applications.
