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Dual-wavelength distributed Bragg reflector semiconductor laser based on a composite resonant cavity 下载免费PDF全文
We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector (DBR) composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing (QWI) technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature. 相似文献
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Polarization mode dispersion (PMD) mitigation is performed using an optical 3R (re-amplification, reshaping, re-timing) regenerator based on electro-absorption modulator (EAM) with wavelength conversion. System performance without and with 3R regeneration was separately studied by eye analysis and bit-error rate (BER) measurements. The signal quality was significantly improved by 3R regeneration under serious first order PMD (up to 40% of the bit interval) combined with second order PMD (up to about 520 ps2). The PMD mitigation margin of the proposed method is also investigated by measuring the sensitivity at BER 10-10. Further studies indicate that 3R regenerators have the potential to combat with the effects of PMD combined with polarization dependent loss (PDL) and polarization hole-burning (PHB). 相似文献
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Theoretical Design of Fibre-Based Digital Autocorrelator for Completely Characterizing Ultrashort Pulses 下载免费PDF全文
A new idea to design fibre-based digital autocorrelation technique for completely characterizing ultrashort pulses is presented. Feasibility of the design is demonstrated by theory. The technique is found to promise minimized optical alignment requirements, compact configuration, high time resolution, and short measurement time. 相似文献
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In-line synchronous modulation as a way of mitigating the signal quality degradation induced by polar ization mode dispersion(PMD)was experimentally studied using 10-Gb/s return to zero signal.Bit error rate of the degraded signal and the synchronously modulated signal under the differential group delay(DGD)values of 10,20,34,and 70 ps was measured and compared.The experimental results showed that in-line synchronous modulation is useful to mitigate the signal quality degeneration induced by PMD.1-dB power penalty reduction was obtained even when the PMD was as high as 70% of the bit interval.The limitation of method is also discussed. 相似文献
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A Fabry-Perot(F-P)etalon and a semiconductor optical amplifier(SOA)were combined to preprocess thedata signals before clock recovery.With this technology in the 10-Gb/s clock recovery utilizing injectionmode-locked laser(IMLL)based on SOA,the amplitude fluctuation and timing jitters caused by thepattern effect in recovered clock pulses were greatly reduced,experimentally.It also demonstrated thatclock could be recovered from the very degraded signals. 相似文献
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A 40-Gb/s optical time division multiplexing (OTDM) return-to-zero (RZ) transmission experiments including a dynamic polarization mode dispersion (PMD) compensation was reported. The dynamic PMD compensator is made up of two-stage four degrees of freedom (DOF). The first stage adopts polarization controller and fixed time-delayed line. The second stage is variable differential group delay (DGD) element. The PMD monitoring technique is based on degree of polarization (DOP) as error signal. A novel practical adaptive optimization algorithm was introduced in dynamic adaptive PMD compensation. The experimental results show that the performance of the PMD compensator is excellent for 40-Gb/s RZ transmission systems with the large DGD. With this compensator, a significant improvement of system performance can be achieved in the eye pattern of a received signal. The first-order compensating ability of the compensator is greater than 30 ps. The second-order compensating ability is greater than 200 ps2. The first 相似文献
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The time-domain ABCD matrix formalism is based on the propagation of a Gaussian pulse which is characterized by the pulsewidth and chirp. In this paper, the time-domain ABCD matrix of th SPM (self phase modulation) is perfected so as to acquire more information. With the time-domain ABCD matrices of amplitude modulation, filtration from the optical bandpass, group velocity dispersion and SPM, the detailed characteristics of actively mode-locked fiber laser are described and the steady-state solutions are derived for two simple cases. The application of the formalism is also helpful to understand the mechanism of mode-locking in an actively mode-locked fiber laser. 相似文献