Chang-Jen Wu

10 m/25 Gbps LiFi transmission system based on a two-stage injection-locked 680 nm VCSEL transmitter.

A 10  m/25  Gbps light-based WiFi (LiFi) transmission system based on a two-stage injection-locked 680 nm vertical-cavity surface-emitting laser (VCSEL) transmitter is proposed. A LiFi transmission system with a data rate of 25 Gbps is experimentally demonstrated over a 10 m free-space link. To the best of our knowledge, it is the first time a two-stage injection-locked 680 nm VCSEL transmitter in a 10  m/25  Gbps LiFi transmission system has been employed. Impressive bit error rate performance and a clear eye diagram are achieved in the proposed systems. Such a 10  m/25  Gbps LiFi transmission system provides the advantage of a communication link for higher data rates that could accelerate the deployment of visible laser light communication.

Bidirectional fiber-wireless and fiber-VLLC transmission system based on an OEO-based BLS and a RSOA.

A bidirectional fiber-wireless and fiber-visible-laser-light-communication (VLLC) transmission system based on an optoelectronic oscillator (OEO)-based broadband light source (BLS) and a reflective semiconductor optical amplifier (RSOA) is proposed and experimentally demonstrated. Through an in-depth observation of such bidirectional fiber-wireless and fiber-VLLC transmission systems, good bit error rate performances are obtained over a 40 km single-mode fiber and a 10 m RF/optical wireless transport. Such a bidirectional fiber-wireless and fiber-VLLC transmission system is an attractive option for providing broadband integrated services.

150 m/280 Gbps WDM/SDM FSO link based on OEO-based BLS and afocal telescopes.

A 150 m/280 Gbps free-space optical (FSO) link based on an optoelectronic oscillator (OEO)-based broadband light source (BLS), afocal telescopes, and wavelength-division-multiplexing (WDM)/space-division-multiplexing (SDM) convergence is proposed. Experimental results show that the transmission distance of FSO links is significantly increased by afocal telescopes, and the transmission rate of FSO links is greatly enhanced by WDM and SDM convergence. With the aid of a low noise amplifier and clock/data recovery, good bit error rate performance and a clear eye diagram are achieved at 150 m/280 Gbps operation. This proposed 150 m/280 Gbps WDM/SDM FSO link is shown to be a prominent alternative not only because of its advancement of indoor FSO communications but also because of the advantages of optical wireless communications for a long transmission distance and high transmission rate.

A 50-m/320-Gb/s DWDM FSO Communication With Afocal Scheme

This paper proposes and presents the experimental demonstration of 320-Gb/s free-space optical (FSO) communication based on dense-wavelength-division-multiplexing (DWDM) technology and afocal scheme. To the best of our knowledge, this is the first one that adopts DWDM technology and afocal scheme to successfully demonstrate 50-m/320-Gb/s FSO communication. Results show that the free-space transmission distance is greatly increased by the afocal scheme and that the free-space transmission rate is significantly enhanced by the DWDM technology. DWDM FSO communication over a 50-m free-space link with a total transmission rate of 320 Gb/s (40 Gb/s/λ × 8λ = 320 Gb/s) is achieved. With the aid of a low-noise amplifier and clock/data recovery at the receiving site, good bit-error-rate (BER) performance and clear eye diagram are obtained at a 50-m/320-Gb/s operation. Such 50-m/320-Gb/s DWDM FSO communication provides the advantages of optical wireless communications for long transmission distance and high transmission rate, which is thoroughly useful for long-haul and high-speed light-based WiFi (LiFi) applications.

A 100 m/320 Gbps SDM FSO link with a doublet lens scheme

A 100 m/320 Gbps space-division-multiplexing (SDM) free-space optical (FSO) link with a doublet lens scheme is proposed and experimentally demonstrated. The transmission capacity of FSO links is increased significantly by the SDM topology, and the transmission distance of FSO links is greatly extended by the doublet lens scheme. An FSO link of eight channels over a 100 m free-space link with a total transmission rate of 320 Gbps (40 Gbps/λ × 8λ = 320 Gbps) is achieved. With the assistance of a low noise amplifier (LNA) and clock/data recovery (CDR) at the receiving site, a good bit error rate (BER) performance and a clear eye diagram are obtained at 100 m/320 Gbps. The proposed 100 m/320 Gbps SDM FSO link is shown to be a notable option to provide the advantages of long transmission distances and high transmission rates for optical wireless communications.

Fiber-Wireless and Fiber-IVLLC Convergences Based on MZM-OEO-Based BLS

Fiber-wireless and fiber-invisible laser light communication (IVLLC) convergences that adopt the Mach-Zehnder modulator-optoelectronic oscillator (MZM-OEO)-based broadband light source for microwave (MW)/millimeter-wave (MMW)/baseband (BB) signal transmission are proposed and demonstrated. For downlink transmission, light is optically promoted from 15- and 25-GHz radio-frequency (RF) signals to 10-Gb/s/30-GHz MW, 15-Gb/s/50-GHz MMW, 20-Gb/s/60-GHz MMW, and 25-Gb/s/100-GHz MMW data signals based on fiber-wireless and fiber-IVLLC integrations. Bit error rate (BER) performs efficiently in the 40-km single-mode fiber (SMF) and the 10-m RF/25-m optical wireless transport scenarios. For uplink transmission, downstream light is successfully intensity-modulated with a 25-Gb/s BB data stream based on fiber-IVLLC integration. BER performs efficiently in the 40-km SMF and the 100-m optical wireless transport scenario. Such a hybrid MW/MMW/BB lightwave transmission system is an attractive alternative. It is shown to be a prominent one to present advancements in integrating fiber backbone and radio-frequency (RF)/optical wireless feeder networks.

A Bidirectional Wireless-Over-Fiber Transport System

This study proposes and demonstrates a bidirectional wireless-over-fiber (WoF) transport system based on an optical interleaver, a phase modulator, and an optical bandpass filter (OBPF)-based phase-modulation-to-intensity-modulation converter that can deliver intensity-modulated 60 GHz millimeter-wave (MMW), 30 GHz microwave (MW), and phase-remodulated 15 GHz MW data signals. A broadband light source, comprising an optoelectronic oscillator scheme and an optical signal-to-noise ratio (OSNR) enhancement scheme, is deployed in these bidirectional 60 GHz/30 GHz/15 GHz WoF transport systems. For downlink transmission, light is promoted optically from a 5 Gbps/ 15 GHz MW data signal to 5 Gbps/60 GHz MMW and 5 Gbps/30 GHz MW data signals in fiber-wireless convergence. The downstream light is phase remodulated successfully using a 5 Gbps/15 GHz MW data signal for uplink transmission. Through a thorough examination of such bidirectional 60 GHz/30 GHz/15 GHz WoF transport systems, the bit error rate (BER) is observed to perform well over a 40 km single-mode fiber and a 4 m RF wireless transmission. This bidirectional 60 GHz/30 GHz/15 GHz WoF transport system is a prominent alternative not only because of its advancement in integrating optical fiber and RF wireless networks but because of the benefits of communication links for broader bandwidth and higher transmission rate as well.

A hybrid lightwave transport system based on a BLS with an OSNR enhancement scheme

A hybrid lightwave transport system based on a broadband light source (BLS) with an optical signal-to-noise ratio (OSNR) enhancement scheme for millimeter-wave (MMW)/radio-over-fiber (RoF)/cable television (CATV) signal transmission is proposed and experimentally demonstrated. Unlike traditional hybrid lightwave transport systems for signal transmission, in which a transmitting site needs multiple wavelength-selected distributed feedback laser diodes (DFB LDs) to support various services, such proposed systems employ a phase modulator to provide multiple optical carriers for various applications. Over an 80 km single-mode fiber (SMF) transmission, the bit error rate (BER)/carrier-to-noise ratio (CNR)/composite second-order (CSO)/composite triple-beat (CTB) perform brilliantly for hybrid 100 GHz MMW/50 GHz MMW/10 GHz RoF/550 MHz CATV signal transmission. Such a hybrid lightwave transport system would be attractive for fiber trunk applications to provide broadband integrated services.