共查询到20条相似文献,搜索用时 15 毫秒
1.
Djordjev K. Sang-Jun Choi Won-Jin Choi Seung-June Choi In Kim Dapkus P.D. 《Photonics Technology Letters, IEEE》2002,14(5):603-605
Spectral equalization devices for an optical analog-to-digital (A-to-D) converting system have been theoretically analyzed and fabricated. Selective area growth was used to define a multiple-section active region. Two-segment semiconductor optical amplifier with current adjustable gain spectrum is demonstrated 相似文献
2.
Kim I. Alferness R.C. Buhl L.L. Koren U. Miller B.I. Young M.G. Newkirk M.A. Chien M.D. Koch T.L. Raybon G. Burrus C.A. 《Photonics Technology Letters, IEEE》1993,5(11):1319-1321
A photonic integrated circuit with an InGaAs/InGaAsP multiple-quantum-well (MQW) traveling-wave optical amplifier and a grating-assisted vertical-coupler filter as a noise filter have been demonstrated. A fiber-to-amplifier/filter gain of ~0.5 dB and a 3-dB filter bandwidth (FWHM) of ~70 Å at 1.56 μm filter center wavelength have been achieved. This photonic circuit is potentially suitable as a building-block for preamplifier lightwave receivers or high-gain, high-power optical amplifiers which are essential for optical communication systems and lightwave networks 相似文献
3.
We present results of a novel semiconductor optical amplifier device in which an amplifier and a phase modulator are integrated into a fundamental transverse-mode ridge waveguide. By placing the p-n junction below the quantum well (QW) during epitaxial growth and utilizing the effect of the electric field on the depletion width, the phase of the light from an integrated optical amplifier-modulator is varied. For a modulation reverse bias voltage range of 0.4 V, we have demonstrated a 360°/mm phase shift with less than 1.2 dB of amplitude modulation 相似文献
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5.
Liu Yang Ye Nan Wang Baojun Zhou Daibing An Xin Bian Jing Pan Jiaoqing Zhao Lingjuan Wang Wei 《半导体学报》2010,31(7)
High output powers and wide range tuning have been achieved in a sampled grating distributed Bragg reflector laser with an integrated semiconductor optical amplifier. Tilted amplifier and anti-reflection facet coating are used to suppress reflection. We have demonstrated sampled grating DBR laser with a tuning range over 38 nm, good wavelength coverage and peak output powers of more than 9 mW for all wavelengths. 相似文献
6.
The influence of output facet reflection on characteristics of a monolithically integrated optical device consisting of a distributed feedback (DFB) laser and an optical amplifier/modulator is analyzed. Basic equations used for the analysis are the characteristic equation for a DFB laser and the rate equations. As a result, it is known that static and dynamic properties of such optical integrated devices are seriously degraded by the optical feedback from the output facet. It is concluded that the power reflectivity of the output facet should be reduced to at least less than 0.1% for the integrated region to work as an optical amplifier and less than 0.01% as an intensity modulator 相似文献
7.
《Microwave Theory and Techniques》1982,30(4):410-421
The noise characteristics in a Fabry-Perot (FP) cavity type semiconductor laser amplifier, biased at just below its oscillation thresh-old current, have been studied theoretically and experimentally. Quantum mechanical multimode rate equations containing a Langevin shot noise source and an input signal term were numerically solved for an exponential band-tail model with no k-selection rule. Noise power calculated using this rate equation was compared with a simpler photon statistic master equation method. The experimental results on noise power for an AlGaAs laser amplifier are in reasonable agreement with the two different theoretical predictions. Dominant noise powers in a semiconductor laser amplifier are beat noise powers between signal and spontaneous emission, and between spontaneous emission components. Noise characteristics in a Fabry-Perot cavity type laser amplifier can be improved both by the reduction of the facet mirror reflectivities and by use of an asymmetric cavity configuration with low-input and high-output mirror reflectivities. Two beat noise powers are expressed in simple analytic form by introducing an equivalent noise bandwidth and an excess noise coefficient as figures of merit in an optical amplifier. 相似文献
8.
Coherent optical fiber communications have been studied intensively because of their high receiver sensitivity and high-frequency selectivity. With the advent of an erbium-doped fiber amplifier (EDFA), however, the first advantage seems to have become less attractive. Nevertheless, the combination of the EDFA and coherent techniques offers a number of attractive features. In this paper, we show both theoretically and experimentally that the excess beat noises (common-mode and image-band beat noises) from optical amplifiers can be suppressed by using coherent receivers such as a balanced receiver and a double-stage phase-diversity (DSPD) receiver. The noise figure (NF) of the excess-noise-suppressed coherent receivers with an optical preamplifier is shown to be 0 dB. Bit-error-rate (BER) formulas are also discussed 相似文献
9.
Noise in an AlGaAs semiconductor laser amplifier 总被引:1,自引:0,他引:1
The noise characteristics in a Fabry-Perot (FP) cavity type semiconductor laser amplifier, biased at just below its oscillation threshold current, have been studied theoretically and experimentally. Quantum mechanical multimode rate equations containing a Langevin shot noise source and an input signal term were numerically solved for an exponential band-tail model with nok -selection rule. Noise power calculated using this rate equation was compared with a simpler photon statistic master equation method. The experimental results on noise power for an AlGaAs laser amplifier are in reasonable agreement with the two different theoretical predictions. Dominant noise powers in a semiconductor laser amplifier are beat noise powers between signal and spontaneous emission, and between spontaneous emission components. Noise characteristics in a Fabry-Perot cavity type laser amplifier can be improved both by the reduction of the facet mirror reflectivities and by use of an asymmetric cavity configuration with low-input and high-output mirror reflectivities. Two beat noise powers are expressed in simple analytic form by introducing an equivalent noise bandwidth and an excess noise coefficient as figures of merit in an optical amplifier. 相似文献
10.
An electroabsorption modulator and an optical amplifier have been monolithically integrated by using nonplanar MOVPE. A bandgap shift of more than 60nm was obtained with atmospheric pressure MOVPE of GaInAs/GaInAsP strained QWs on 10 mu m wide ridges. A chip gain of 9dB and an excitation ratio of 17dB were obtained for the monolithic electroabsorption modulator/amplifier. The integration of an optical amplifier enables the use of a wavelength close to the bandgap of the modulator, resulting in low voltage and low chirp operation.<> 相似文献
11.
Liou K.-Y. Koren U. Burrows E.C. Oron M. Miller B.I. Young M. Raybon G. Burrus C.A. 《Photonics Technology Letters, IEEE》1990,2(12):878-880
Monolithic integration of a monitoring detector with an optical amplifier simplifies the use of an amplifier in lightwave systems. The structure and performance are described of a monolithically integrated semiconductor optical amplifier with low-loss Y -branching waveguides and a monitoring p-i-n detector. The photocurrent of the integrated detector can be used as a single control parameter for amplifier output leveling, gain optimization, and in situ monitoring of facet antireflective coatings 相似文献
12.
We theoretically explored the system limits of various single- and multichannel transmission links employing semiconductor optical amplifiers (SOAs). For this purpose, we developed an accurate model to describe the amplifier dynamics in the moderate and low saturation regimes. Our simulation results revealed the delicate balance among the level of saturation, the signal-to-noise ratio, and the amount of gain per amplifier required for optimum system performance. The modeling results have been confirmed by recent experimental work in this area 相似文献
13.
Gustavsson M. Lagerstrom B. Thylen L. Janson M. Lundgren L. Morner A.-C. Rask M. Stoltz B. 《Electronics letters》1992,28(24):2223-2225
Monolithically integrated 4*4 semiconductor laser amplifier gate switch arrays comprising 24 integrated laser amplifiers have been fabricated and evaluated. Net positive optical gain between fibres, high extinction ratio, and low crosstalk are reported.<> 相似文献
14.
Heck M.J.R. Bente A.J.M. Barbarin Y. Lenstra D. Smit M.K. 《Quantum Electronics, IEEE Journal of》2007,43(10):910-922
In this paper, a waveguide device concept, named IRIS, is presented. The device consists of a monolithic array of concatenated semiconductor optical amplifiers and saturable absorbers. We have theoretically investigated picosecond pulse transmission through these devices. The parameters used in the simulation are representative for InP-InGaAsP bulk gain material, operating in the 1550-nm region. Operated as an optical amplifier for picosecond pulses, the simulation results show increased pulse peak amplification and decreased temporal broadening of the pulses for the IRIS devices as compared to a semiconductor optical amplifier of equivalent length. Used as a nonlinear element to increase the optical bandwidth of a picosecond pulse, the spectra obtained with IRIS devices show an increased broadening and smoothness as compared to a semiconductor optical amplifier. Finally the feasibility for using the IRIS device as an optical isolator is shown. It is operated in a regime where the device is transparent for a picosecond pulse train, while it is absorbent for lower power reflections. 相似文献
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16.
掺铒光纤放大器的偏振相关增益是导致放大器增益不平坦的一个重要原因,进而影响长距离光纤通信系统、长距离光纤传感系统的信号质量.本文从理论模拟角度研究了级联掺铒光纤放大器的偏振相关增益对光纤中所传输通信光信号的影响.重点研究了掺铒光纤非均匀展宽情况下,偏振相关增益受传输信号功率、信道个数、级联EDFA个数、等因素的影响,并给出了定性结论. 相似文献
17.
We have experimentally observed and theoretically analyzed the gain dependent optimum repetition rates of a hybrid-type active and passive mode locked laser pulses in an erbium-doped fiber laser of the figure-of-eight geometry by utilizing a nonlinear amplifier loop mirror (NALM) as a saturable absorber and a directional-coupler type electro-optic modulator as an active mode locker. Transform-limited mode-locked pulses of about 10 ps width were obtained at repetition rates which correspond to harmonics of the cavity fundamental frequency and depend on the optical amplifier gain in the NALM. 相似文献
18.
Ryu S. Yamamoto S. Taga H. Edagawa N. Yoshida Y. Wakabayashi H. 《Lightwave Technology, Journal of》1991,9(2):251-260
Studies on long-haul coherent optical fiber communication systems with in-line optical amplifier repeaters are made theoretically and experimentally. By theoretical calculation it was found that coherent systems can achieve wider dynamic range for an amplifier input power as compared with the intensity-modulation direct-detection (IM-DD) systems. The feasibility of such systems using traveling-wave semiconductor laser amplifiers (TWSLAs) and erbium-doped fiber amplifiers (EDFAs) was investigated, and 546 km, 140 Mb/s CPFSK transmission using TWSLAs and 1028-km, 560-Mb/s CPFSK transmission using EDFAs were successfully demonstrated 相似文献
19.
40-Gb/s tandem electroabsorption modulator 总被引:3,自引:0,他引:3
Mason B. Ougazzaden A. Lentz C.W. Glogovsky K.G. Reynolds C.L. Przybylek G.J. Leibenguth R.E. Kercher T.L. Boardman J.W. Rader M.T. Geary J.M. Walters F.S. Peticolas L.J. Freund J.M. Chu S.N.G. Sirenko A. Jurchenko R.J. Hybertsen M.S. Ketelsen L.J.P. Raybon G. 《Photonics Technology Letters, IEEE》2002,14(1):27-29
In this letter, we have developed a tandem electroabsorption modulator with an integrated semiconductor optical amplifier that is capable of both nonreturn-to-zero and return-to-zero (RZ) data transmission at 40 Gb/s. The tandem modulator consists of a broad-band data encoder and a narrow-band pulse carver. The pulse carver is able to produce 5-ps pulses with more than 20 dB of extinction. The on-chip semiconductor optical amplifier provides up to 8.5 dB of fiber-to-fiber gain and enables the modulator to be operated with zero insertion loss. Devices have been realized with greater than 40-GHz bandwidth, and 13-dB dynamic extinction for a 2.5-V swing. For optimized designs bandwidths of nearly 60 GHz: have been realized. Using these devices penalty free RZ data transmission over a 100-kin dispersion compensated fiber link has been demonstrated with a received power sensitivity of -29 dBm 相似文献