共查询到20条相似文献,搜索用时 31 毫秒
1.
A theory for pulse amplification and saturation in quantum dot (QD) semiconductor optical amplifiers (SOAs) is developed. In particular, the maximum bit rate at which a data stream of pulses can be amplified without significant patterning effects is investigated. Simple expressions are derived that clearly show the dependence of the maximum bit rate on material and device parameters. A comparative analysis of QD, quantum well (QW), and bulk SOAs shows that QD SOAs may have superior properties; calculations predict patterning-free amplification up to bit rates of /spl sim/150-200 Gb/s with pulse output energies of /spl sim/0.2-0.4 pJ. The superiority of QD SOAs is based on: 1) the faster achievement of the regime of maximum gain in QD SOAs compared to QW and bulk SOAs and 2) the lower effective cross section of photon-carrier interaction in QDs. 相似文献
2.
《Quantum Electronics, IEEE Journal of》2009,45(11):1429-1435
3.
Semiconductor optical amplifiers in WDM tree-net 总被引:1,自引:0,他引:1
In this paper, effectiveness of semiconductor optical amplifiers (SOAs) in tree-net in terms of increase in the number of users has been investigated. In the analysis, SOAs with (i) unsaturated gain, (ii) average gain saturation, and (iii) average gain saturation with gain fluctuations have been considered. Further, the results for the tree-net are compared with those for the star network. It is observed that tree-net supports more number of users than star for a given number of SOAs 相似文献
4.
Analytical Solution for SOA-Based All-Optical Wavelength Conversion Using Transient Cross-Phase Modulation 总被引:1,自引:0,他引:1
Dong J. Fu S. Zhang X. Shum P. Zhang L. Huang D. 《Photonics Technology Letters, IEEE》2006,18(24):2554-2556
All-optical wavelength conversion (WC) based on transient cross-phase modulation (T-XPM) of semiconductor optical amplifier (SOAs) is a promising approach to accelerate the gain recovery of SOAs. An analytical solution is deduced to explain the polarity variation of WC based on T-XPM of SOAs from the viewpoint of the impulse response functions. We conclude that both inverted and noninverted WCs can be realized when the central wavelength of the optical bandpass filter is either blue-shifted or red-shifted with respect to the wavelength of the probe signal. We are able to validate the formula against our experimental results recently published 相似文献
5.
Transmission performance of 10-Gb/s 1550-nm transmitters using semiconductor optical amplifiers as booster amplifiers 总被引:1,自引:0,他引:1
Yonggyoo Kim Hodeok Jang Yonghoon Kim Jeongsuk Lee Donghoon Jang Jichai Jeong 《Lightwave Technology, Journal of》2003,21(2):476-481
We have demonstrated the transmission performance of 10-Gb/s transmitters based on LiNbO/sub 3/ modulator using semiconductor optical amplifiers (SOAs) as booster amplifiers. Utilizing the negative chirp converted in SOAs and self-phase modulation induced by high optical power, we can successfully transmit 10-Gb/s optical signals over 80 km through the standard single-mode fiber with the transmitter using SOAs as booster amplifiers. SOAs can be used for booster amplifiers with a careful adjustment of the operating conditions. In order to further understand an SOA's characteristics as a booster amplifier, we model SOAs and other subsystems to verify the experimental results. Based on the good agreement between the experimental and simulation results, we can find the appropriate parameters of input signals for SOAs, such as extinction ratio, rising/falling time, and chirp parameter to maximize output dynamic range and available maximum output power (P/sub o,max/). 相似文献
6.
Woosuk Choi Sub Hur Jaehoon Lee Yonggyoo Kim Jichai Jeong 《Lightwave Technology, Journal of》2002,20(8):1350-1356
We have analyzed the transmission performance of 8/spl times/10 Gb/s wavelength division multiplexing (WDM) signals due to crosstalk in cascaded conventional semiconductor optical amplifiers (SOAs). Using two different methods, the crosstalk over the whole gain bandwidth in SOAs is calculated to be 2-5 dB lower for the positive detuning. Then, transmission performance of 8/spl times/10 Gb/s WDM signals up to 6/spl times/40 km span in terms of receiver sensitivity is estimated over various transmission distances using cascaded SOAs for the positive signal wavelength displacement of 30, 40, and 50 nm. Especially for 50 nm detuning, transmission performances with and without using a reservoir channel are similar to each other. Our results suggest that SOAs can be used as an optical amplifier for displacement larger than 50 nm without using the reservoir channel. 相似文献
7.
Tang J.M. Spencer P.S. Rees P. Shore K.A. 《Quantum Electronics, IEEE Journal of》2000,36(12):1462-1467
A numerical investigation is performed of the characteristics of the pump-power dependent transparency carrier density of semiconductor optical amplifiers (SOAs) in pump-probe configurations. The simulations show good agreement with published experimental measurements. It is found that both gain compression due to two-photon absorption (TPA) and TPA carrier generation are crucial in determining the behavior of SOAs at transparency. In particular, a novel technique for significantly reducing the pump-power dependence of the transparency carrier density is proposed. Calculations also indicate that, by using negative frequency detuned probe and pump pulses, SOAs with fixed-transparency carrier densities can be obtained for a large pump energy range 相似文献
8.
An ultrafast all-optical logic AND gate is realised based on two cascaded Semiconductor optical amplifiers (SOAs) each followed by an optical filter to accelerate the effective recovery process of the SOAs. 40 Gbit/s operation with return-to-zero signals has been achieved with SOAs, the 90-10% recovery time of which is much greater than the single bit period. Clear open eyes with quality factor of 6.3 are observed. The proposed AND gate has a potentially loose requirement on input pulse width 相似文献
9.
Thermal and Optical Characterization of Photonic Integrated Circuits by Thermoreflectance Microscopy
《Quantum Electronics, IEEE Journal of》2010,46(1):3-10
10.
半导体光放大器(SOA)作为全光集成器件的核心,在全光通信和光纤传感等领域中具有重要的应用前景。值得关注的是,半导体光放大器的材料增益透明决定了它的快慢光过渡点和信号增益的起始点,因此准确测量其材料增益透明对应的注入电流,对于SOA的全面应用具有重要意义。提出了一种测量SOA材料增益透明电流的方法,并深入分析了其特点。依据材料增益透明时SOA的输出功率与入射光偏振无关的特性,实验测量了不同输入光功率条件下,入射光偏振态对输出功率影响最小时,SOA的注入电流。利用上述方法,准确地测量出给定波长输入待测SOA的增益透明电流为155mA。该方法为实现其他类型任意波长注入时SOA增益透明电流的测量提供了参考,为其全面应用奠定了基础。 相似文献
11.
12.
The safe operating area (SOA) of GaAs-based heterojunction bipolar transistors has been studied considering both the self-heating effect and the breakdown effect. The Kirk effect induced breakdown (KIB) was considered to account for the decrease of the breakdown voltage at high currents. With reasonable emitter ballastors, the KIB effect was shown to be the major cause for device failure at high currents, while the thermal effect controls the low current failure. The effect of emitter resistance and base resistance on device stability was also studied. While the emitter resistance always improves the device stability by expanding the SOAs, the base resistance degrades SOAs when the KIB dominates the failure mechanism. The effect of the base resistance on SOAs was explained by its control on the flow of the avalanche current. Since the KIB effect depends on the collector structure, it was shown that a nonuniformly doped collector can effectively improve the SOAs 相似文献
13.
Sub Hur Jeongyun Ko Inkyu Lee Kim Y.S. Jichai Jeong 《Lightwave Technology, Journal of》2003,21(6):1499-1503
We have theoretically investigated 8 /spl times/ 10-Gb/s wavelength-division multiplexing (WDM) signal transmission characteristics based on semiconductor optical amplifiers (SOAs) with equalized gain using discrete Raman amplification (DRA). Gain equalization and low noise figures have been obtained by adjusting the backward Raman pumping power and wavelength at a dispersion compensating fiber (DCF) for each span. Bit-error-rate characteristics were calculated for 8 /spl times/ 10-Gb/s WDM signal transmission over 6 /spl times/ 40-km single-mode fiber (SMF) + DCF links with gain-equalized SOAs using DRAs at DCF. Approximately a 2.5-dB improvement of the receiver sensitivity was achieved by using SOAs and DRAs with optimized Raman pumping. One can easily upgrade the transmission length of a link based on SOAs with an appropriate backward pump laser at each DCF. 相似文献
14.
The penalty imposed on the multichannel wavelength-division multiplexing (WDM) link employing cascaded semiconductor optical amplifiers (SOAs) caused by the cross-gain modulation (XGM) in the SOAs is analyzed and shown to depend on the dispersion management scheme utilized in the link. Based on the results of the analysis, a novel dispersion management scheme is proposed to prevent the repetition of the bit patterns at each SOA stage. Numerical calculations show that with the proposed dispersion management scheme, the crosstalk is mitigated and the performance is significantly improved. 相似文献
15.
The conversion efficiency and output signal-to-noise ratio (SNR) of single-pump four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is strongly dependent on frequency shift. We examine a scheme for FWM in SOAs that uses two orthogonally polarized pumps. We compare experimentally and theoretically the conversion efficiency and SNR of the orthogonal-pump scheme with single-pump FWM. The orthogonal-pump scheme has nearly constant conversion efficiency and SNR over the 4.5-THz range of frequency shifts measured. Experimental and theoretical results for the conversion efficiency and SNR of the orthogonal-pump scheme agree to within 3.5 dB 相似文献
16.
The authors present a novel all-optical logic NOR gate using two-cascaded semiconductor optical. amplifiers (SOAs) in a counterpropagating feedback configuration. This configuration accentuates the gain nonlinearity due to the mutual gain modulation of the two SOAs. The all-optical NOR gate feasibility has been demonstrated delivering an extinction ratio higher than 12 dB over a wide range of wavelength. 相似文献
17.
We will review three recently-proposed high-speed, all-optical Exclusive OR (XOR) gates operating at 40 and 85?Gb/s, which were demonstrated using ultrafast nonlinear interferometers (UNIs) incorporating semiconductor optical amplifiers (SOAs). The first 40-Gb/s XOR gate was obtained using a dual UNI configuration. The second is a 40-Gb/s XOR gate without additional probe beam required, where the only inputs launched into the setup were data A and B. The XOR logic of data A and B is the sum of two components (A)B and(A)B , each of which was obtained from the output of UNI via cross-phase modulation (XPM) in SOAs. Furthermore, an 85-Gb/s XOR gate is, by far, the fastest XOR gate realized by SOAs, which was also demonstrated using a dual UNI structure. The operating speed of the XOR gate was enhanced by incorporating the recently proposed turbo-switch configuration. In addition, the SOA switching pulse energies of these XOR gates were lower than 100 fJ. 相似文献
18.
Ciaramella E. D'Errico A. Proietti R. Contestabile G. 《Lightwave Technology, Journal of》2006,24(11):4039-4046
The authors demonstrate the potential of using POLarization Shift Keying (POLSK) modulation format combined with semiconductor optical amplifiers (SOAs) in wavelength division multiplexing (WDM) transmission systems. The constant intensity of the POLSK modulation format allows for substantial removal of cross-gain-modulation impairments in SOAs so that practical amplifier spacing values (more than 100 km) are demonstrated in various different experimental configurations. Record WDM transmission experiments at 10 Gb/s by using SOA-based amplification are presented in short and medium reach system architectures using either single mode fiber or nonzero dispersion shifted fiber 相似文献
19.
Zhang L. Kang I. Bhardwaj A. Sauer N. Cabot S. Jaques J. Neilson D. T. 《Photonics Technology Letters, IEEE》2006,18(22):2323-2325
The effect of p-type doping of the active region of multiple quantum-well (MQW) semiconductor optical amplifiers (SOAs) has been studied. Spectrogram measurements of the dynamics of the SOAs reveal that using p-doped barriers for the MQWs has significantly reduced both gain and phase recovery times. 1/e phase recovery times as short as 11 ps were demonstrated using this approach 相似文献
20.
Time and spectral domain properties of distributed-feedback-type gain-clamped semiconductor optical amplifiers 总被引:1,自引:0,他引:1
G.-X. Chen W. Li C.-L. Xu W.-P. Huang S.-S. Jian 《Photonics Technology Letters, IEEE》2006,18(8):932-934
A comprehensive model for the analysis of distributed-feedback (DFB)-type semiconductor optical amplifiers (SOAs) both in time- and frequency-domain is developed by combination of a wideband field-based traveling-wave rate equation model and an extended transfer matrix formalism for corrugated structures derived in spectral domain. The numerical implementation of the model is successfully fulfilled by dividing the device into many short segments along the cavity length. Based on this unique model, some time- and spectral-domain properties, such as amplified spontaneous emission, laser action, and signal amplification of DFB-type gain-clamped SOAs are simulated and analyzed. 相似文献