Browsing by Author "Chen, Jhao-Ren"

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An Erbium Fiber Laser With Single-Frequency Oscillation and Wavelength-Upconverted Output
(2020-10-01)
Yeh, Chien-Hung
;
You, Wei-Yao
;
Chen, Jhao-Ren
;
Chow, Chi-Wai
;
Lin, Wen-Piao
In this paper, we present experimentally an erbium-doped fiber (EDF) laser system to accomplish the single-longitudinal-mode (SLM) and wavelength-upconverted output by using nonlinear effect. To accomplish the SLM output, a short length of unpumped EDF saturable absorber (SA) is applied inside the EDF laser cavity for filtering densely multi-mode noise. In accordance with the designed EDF laser system, the lasing wavelength can be upconverted to a longer wavelength position. In addition, the output characteristics of output power, optical signal to noise ratio (OSNR), tunability, stability and linewidth in the EDF laser are also discussed.
Free Space Optical Communication in Long-Reach Unidirectional Ring-Architecture Fiber Network
(2020-01-01)
Yeh, Chien-Hung
;
Chen, Jhao-Ren
;
You, Wei-Yao
;
Lin, Wen-Piao
;
Chow, Chi-Wai
In the work, a ring-constructed wavelength-division-multiplexing (WDM) access system for delivering multiple free space optical (FSO) wireless signals is investigated. To reach the FSO transmission through single-mode fiber (SMF) connection, the optical wireless unit (OWU) and remote OWU are designed in the WDM network. The downstream and upstream WDM FSO channels could be transmitted in unidirectional propagation with the same wavelength. Hence, the presented ring-based WDM network not only can transmit the FSO signal, but also can circumvent the Rayleigh backscattering (RB) interferometric beat noise. In addition, according to the experimental results, the SMF and FSO transmission lengths can reach 50 km and 500 to 1000 m at the forward error correction (FEC) level without using optical amplification and dispersion compensation, respectively, when four WDM wavelengths are exploited experimentally for demonstration.
Hybrid WDM FSO Fiber Access Network With Rayleigh Backscattering Noise Mitigation
(2020-01-01)
Yeh, Chien-Hung
;
Chen, Jhao-Ren
;
You, Wei-Yao
;
Chow, Chi-Wai
;
光電工程學系
In the paper, we present and investigate an integrated wavelength-division-multiplexing (WDM) free space optical (FSO) fiber access network for 51 km long-reach connection. Here, the proposed network architecture also can mitigate Rayleigh backscattering (RB) interferometric beat noise. We employ symmetric 4 x 10 Gbit/s on-off keying (OOK) WDM-FSO downstream and upstream wavelengths for demonstration. According to the simulated and experimental results, the free space transmission length of 400 to 940 m can be achieved based on various WDM-FSO downstream signals and their corresponding power budget, when the wavelengths are without optical amplification.
Rayleigh Backscattering Noise Alleviation in Long-Reach Ring-Based WDM Access Communication
(2020-01-01)
Yeh, Chieg-Hua
;
Chen, Jhao-Ren
;
You, Wei-Yao
;
Lin, Wen-Piao
;
Chow, Chi-Wai
In the paper, we propose and design a ring-topology wavelength-division-multiplexing (WDM) access network for long-reach signal transmission. Here, the new central office (CO) and optical network unit (ONU) modules are designed to construct the ring-based architecture for symmetric data connection. Thus, the Rayleigh backscattering (RB) beat noise can be prevented due to the unidirectional downstream and upstream signal connections. In the demonstration, eight WDM wavelengths with 10 Gbit/s on-off keying (OOK) modulation are applied to serve as the symmetric downstream and upstream traffic through 105 km fiber connection without dispersion compensation. In addition, the minimum power budgets of 33.8, 36.1 and 35.4 dB among the eight WDM wavelengths can be obtained at the back-to-back (BtB), 51 and 105 km fiber links, respectively, under the forward error correction (FEC) target.
Utilizing self-injection Rayleigh backscattering feedback for channel-selected erbium laser with single-longitudinal-mode output
(2020-07-01)
Yeh, Chien-Hung
;
You, Wei-Yao
;
Chen, Jhao-Ren
;
Chow, Chi-Wai
;
Lin, Wen-Piao
To achieve the target of single-longitudinal-mode (SLM) operation in erbium-doped fiber (EDF) laser, a self-injected Rayleigh backscattering (RBS) feedback schematic is proposed and demonstrated experimentally. Based on the proposed RBS effect, the multi-longitudinal-mode (MLM) noises of the RBS EDF laser can be suppressed fully. Here, the output powers of -7.5 to -5.1 dBm are detected over the tuning bandwidth of 1523.0 to 1563.0 nm. Moreover, the optical signal to noise ratios (OSNRs) of 30.9 and 33.1 dB is also attained. In this study, the SLM oscillation and output instability of the EDF laser are also analyzed and discussed.