Browsing by Author "Peng, WR"

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A cost-effective fast frequency-hopped code-division multiple-access light source using self-seeded Fabry-Perot laser with fiber Bragg grating array
(2004-11-01)
Peng, WR
;
Peng, PC
;
Lin, WP
;
Hsu, KC
;
Lai, YC
We propose a novel light source for the optical fast frequency-hopped code-division multiple-access scheme using a self-seeded gain-switched Fabry-Perot laser diode (FP-LD) with the reconfigurable fiber Bragg grating array (FBGA). The embedded FBGA in the external cavity loop encodes the input pulses both temporally and spectrally. Before feeding back into the FP-LD, the encoded optical pulses propagate the FBGA with reverse direction and are again temporally combined. With the corporation of the variable fiber delay line, the limitation of the pulse rate by the fixed external cavity length is removed and makes the scheme more flexible. The output with sidemode suppression ratio of more than 20 dB has been obtained. With three fiber Bragg gratings on the FBGA, we demonstrate the encoded chip rate of 1.425 GHz under the driving radio frequency of 475 MHz. It is proved that a different codeword can be generated by simply reconfiguring the encoder without changing the rest of the experimental setup.
A novel scheme for better performance in optical code-division multiple access
(2005)
Peng, WR
;
Lin, WP
;
Chien, HC
;
Chi, S
;
交大名義發表
A new spectra-interleaved scheme for passive optical fast frequency-hopped code-division multiple access system is proposed. Interference and bit error rate are improved by numerical result with this new scheme.
Dynamic encoder/decoder based on fiber Bragg gratings for optical security system
(2004-12-01)
Peng, PC
;
Peng, WR
;
Lin, WP
;
Chi, S
;
光電工程學系
A novel dynamic encoder/decoder based on fiber Bragg gratings for optical security systems is presented in this paper. The encoded and decoded optical communication signals can be realized by controlling the optical switches and fiber Bragg grating arrangement. We describe the system operation principle and set up an experimental encoder/decoder to demonstrate the feasibility of the proposed scheme.
Dynamic wavelength allocation in wavelength division multiplexing radio-over-fiber access network
(2005-03-01)
Lin, WP
;
Peng, WR
;
Chi, S
;
光電工程學系
;
Department of Photonics
We demonstrate that dynamic wavelength add-drop multiplexing technology based on a fiber Bragg grating array (FBGA) can be used to improve the efficiency of wavelengths at a burst traffic load for wavelength division multiplexing radio-over-fiber (ROF) access networks. Moreover, we also propose an upstream injection-locked longitudinal mode scheme in a remote node to offer a simple ROF interface. Experimental results demonstrate that these technologies can provide robust and reliable characteristics for large radio terminals.
Encoding ASK labeled CSRZ-DPSK payload by using only one dual-drive Mach-Zehnder modulator with enhanced label performance
(2005-10-01)
Peng, WR
;
Lu, YC
;
Chen, J
;
Chi, S
;
光電工程學系
This theoretical study presents a novel modulation scheme which simultaneously encodes the amplitude shift keying label on the carrier-suppressed return-to-zero differential phase shift keying payload using only one dual-drive Mach-Zehnder modulator. Compared with the previous scheme, in which three optical modulators are required, we offer a simple, compact, and cost-effective method. We theoretically evaluate and simulate the performance differences between the two schemes. It is found that the sensitivity of the label is 2 dB better than the previous scheme and the payload, with optimized extinction ratio in the electroabsorption eraser, has almost the same performance after 120-km standard single-mode fiber transmission.
Generation of wavelength-tunable optical pulses using EDFA as external-injection light source and amplifier for Fabry-Perot laser diode
(2004-11-01)
Peng, PC
;
Peng, WR
;
Lin, JH
;
Lin, WP
;
Chi, S
We propose and experimentally demonstrate a system for the generation of wavelength-tunable pulses using a gain-switched Fabry-Perot laser diode (FPLD) and an erbium-doped fiber amplifier (EDFA). The EDFA is used as both an external-injection light source and an amplifier for the FPLD. The wavelength tuning is achieved by a tunable filter. The optical sidemode suppression ratio of this system is better than 32 dB over the wavelength-tunable range of 34.5 nm. Moreover, the repetition frequency is 2000 MHz, and the pulsewidth is between 49.3 and 65.3 ps. The whole system is simple and can be easily constructed.
Improved fiber Bragg grating array OFFH-CDMA system using a novel frequency-overlapping multigroup method
(2006-03-01)
Peng, WR
;
Lin, WP
;
Chi, S
;
光電工程學系
;
Department of Photonics
The authors propose a novel frequency-overlapping multigroup scheme for a passive all-optical fast-frequency hopped code-division multiple-access (OFFH-CDMA) system based on fiber Bragg grating array (FBGA). In the conventional scheme, the users are assigned those codes constructed on the nonoverlapping frequency slots, and therefore the bandgaps; between the adjacent gratings are wasted. To make a more efficient use of the optical spectrum, the proposed scheme divided the users into several groups, and assigned the codes, which interleaved to each other to the different groups. In addition to the higher utilization of the spectrum, the interleaved nature of the frequency allocations of different groups will make the groups less correlated and, hence, lower the multiple-access interference (MAI). The corresponding codeset and its constraints for this new scheme are also developed and analyzed. The performance of the system in terms of the correlation functions and bit error rate (BER) are given in both the conventional and the proposed schemes. The numerical results show that, with the multigroup scheme, performance is much improved compared to the conventional scheme.
Improved SPM tolerance and cost-effective phase-modulation duobinary transmission over 230-km standard single-mode fiber using a single Mach-Zehnder modulator
(2005-12-01)
Lu, YC
;
Chen, J
;
Feng, KM
;
Yeh, PC
;
Huang, TY
This letter proposes and experimentally demonstrates a cost-effective phase-modulation duobinary modulation scheme for improving self-phase modulation tolerance using a single modulator. Successful transmission over 230 km of standard single-mode fiber was achieved.
Long-distance FBG sensor system using fiber ring laser with hybrid amplifier
(2005)
Peng, PC
;
Feng, KM
;
Peng, WR
;
Chiou, HY
;
Chang, CC
A fiber Bragg grating (FBG) sensor system using a fiber ring laser with a hybrid amplifier is proposed and demonstrated. The hybrid amplifier comprises an erbium doped waveguide amplifier and a semiconductor optical amplifier. The experiment shows that such the hybrid amplifier has a high amplifier spontaneous emission power and gain spectrum. Moreover, this fiber ring laser can provide a stable multiwavelength output with an optical signal-to-noise ratio over 50 dB even if the FBGs are located at a 25 kin remote sensing position.
Long-distance fiber grating sensor system using a fiber ring laser with EDWA and SOA
(2005-08-01)
Peng, PC
;
Feng, KM
;
Peng, WR
;
Chiou, HY
;
Chang, CC
This investigation presents and demonstrates the feasibility of a novel fiber Bragg grating (FBG) sensor system using a fiber ring laser with a hybrid amplifier. The hybrid amplifier comprises an erbium-doped waveguide amplifier (EDWA) and a semiconductor optical amplifier (SOA). Experimental results demonstrate that the hybrid amplifier has a higher amplifier spontaneous emission power and gain spectrum. Moreover, this novel fiber ring laser provides a stable multiwavelength output with an optical signal-to-noise ratio over 50 dB, even when FBGs are located at a 25 km remote sensing position. The primary feature of the proposed fiber laser is that it facilitates a long-distance or a large-scale sensor system. (C) 2005 Elsevier B.V. All rights reserved.
OCDMA light source using directly modulated Fabry-Perot laser diode in an external injection scheme
(2006-05-01)
Peng, PC
;
Peng, WR
;
Feng, KM
;
Chiou, HY
;
Chen, J
This investigation proposes and experimentally demonstrates an optical code-division multiple-access (OCDMA) light source using a directly modulated Fabry-Perot laser diode in an external injection scheme. This light source has an optical sidemode suppression ratio of over 27.5 dB and a pulsewidth of around 55 ps. Such a narrow pulsewidth has great potential for a two-dimensional OCDMA system. Additionally, the bit-error-rate performance with a 2(31) - 1 pseudorandom bit sequence indicates the feasibility of this light source in a 2.488-Gb/s system application.
Performance comparisons between direct NRZ and gain-switched RZ modulation on Fabry-Perot lasers
(2005)
Peng, WR
;
Peng, PC
;
Chen, J
;
Tsai, SY
;
Chi, S
We firstly study the performance comparisons between direct non-return to zero and gain-switched return to zero data formats on a Fabry-Perot laser. With high speed electrical AND gate, we also investigate the relation between the pulse width of electrical drive signal and the quality of optical eye diagrams. It is found that shorter pulse width of electrical signal can completely eliminate the pattern effect and the sensitivity of RZ format is 3.8-dB better than NRZ format at data rate = 2.488-Gbps.
Performance comparisons of external modulated hybrid analog-digital signals in electrical and optical domains
(2005-11-01)
Peng, WR
;
Peng, PC
;
Hsueh, YT
;
Feng, KM
;
Chi, S
A multipurpose network which integrates the functionalities of single radio channel and baseband data distribution has been proposed recently. In this letter, we further propose and compare two possible combination schemes which combine multiple radio channel and single digital baseband data in electrical and optical domains. Linearity of multiple radio channels and performance of digital baseband data are studied in this externally modulated hybrid analog-digital link. It is found that signals combined in the optical domain, while with higher cost, will outperform that in the electrical domain on the carrier-to-noise and distortion ratio. In addition, the baseband data performance is also improved with optical combining scheme since the optimum required modulation index is lower.