Analysis of ASE Injection-locked Colorless Weak-Resonant-Cavity FP-LD Based WDM-PON
Date Issued
2008
Date
2008
Author(s)
Cheng, Tzu-Kang
Abstract
In this thesis, we use amplified spontaneous emission injection-locked reflective semiconductor optical amplifier directly modulated at 622 Mbit/s and 1.25 Gbit/sec with detuning injection-locked mode for quasi-color-free transmission in DWDM-PON system with channel spacing of 200 GHz. With biased current changing from 0.9 Ith to 1.4 Ith, the improvement on receiving power sensitivity for the WRC-FPLD based WDM-PON transmitter is up to 9 dB at bit-error-rate (BER) of 10-9. Increasing the injection-locked mode number from 2 to 3 within temperature variation of 6oC effectively promotes the BER from 10-8 to 10-10 at receiving power of -27 dBm associated with a decreasing power penalty of -3.2 dB. In addition, ASE power and injection-locked mode number dependent frequency chirp and bit error rate responses of a weak-resonant-cavity Fabry-Perot laser diode (WRC-FPLD) transmitter in wavelength division multiplexing passive optical network are characterized. Chirp analysis of upstream data from the 1.25Gbit/s directly modulated WRC-FPLD with two or three injection-locked modes after the 200GHz AWG filtered ASE injection-locking is determined, which reveals the peak-to-peak chirps of -0.8 and -1 GHz with corresponding negative chirp parameters of -1.6 and -2 MHz/ps for two- and three-mode lasing WRC-FPLD, respectively. Such a negative chirp further enlarges to -6.4 and -9 GHz after 25-km single-mode fiber (SMF-28) transmission. The BER of below 10-9 at receiving power below –30 dBm is obtained with mode number dependent power penalty of <0.25 dB before and after 25 km SMF-28 transmission. A chirp model involved the ASE injection induced power saturation effect is derived to explain the negatively frequency chirped WRC-FPLD, which reveals a reverse trend with increasing ASE injection power due to the power-saturation induced on/off extinction ratio reduction (from 10.5 to 8.2 dB) and rising-time broadening (from 120 to 180 ps) on WRC-FPLD transmitted data shape, which effectively reduces the peak-to-peak chirp by at least 2 GHz after 25-km SMF transmission. Furthermore, the effect of AWG filter bandwidth on the transmission performances of the amplified spontaneous emission injection-locked Fabry-Perot laser diode based 1.25 Gbit/s direct modulated DWDM-PON transmitter, in which the DWDM AWG filter with two different channel spacings of 50 and 200 GHz for effectively raising network capacities and reducing the crosstalk induced by interfered reflection are compared. By filtering the ASE source with another 200 GHz AWG filter local ONU part, the AWG induced reflection is minimized to improve the upstream data with a negative power penalty of 1.6 dB. In contrast, the use of a 50 GHz channel-spaings AWG is unable to promote a better BER, where as leading to a power penalty of 1.5 dB for the back-to-back transmission case due to the slight increasing ratio of RIN noise to signal intensity are compared to the 200 GHz AWG based system.
Subjects
WDM
FPLD
CHIRP
Type
thesis
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