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1.
High-power operation in 0.98-μm strained-layer InGaAs-GaAssingle-quantum-well ridge waveguide lasers
High power strained-layer InGaAs-GaAs graded-index separate confinement heterostructure (GRIN-SCH) single-quantum-well (SQW) lasers at an emission wavelength of 0.98 μm have been fabricated. A light power as high as 270 mW and a maximum front power conversion efficiency of 51.5% have been obtained for the antireflective and highly-reflective coated laser with 9-μm-wide ridge and 600-μm-long cavity 相似文献
2.
Schaafsma D.T. Shaw L.B. Cole B. Sanghera J.S. Aggarwal D. 《Photonics Technology Letters, IEEE》1998,10(11):1548-1550
We present a model for optical amplification at 1.3 μm using Dy 3+ in fibers made from a low phonon energy glass, based on GeAsSe. This model uses in-band pumping at 1.28 μm, takes into account the spectral distribution of amplified spontaneous emission, and allows for bottlenecking of excited ions into the intermediate states in Dy as well as the excited state absorption (ESA) from those levels. Using data obtained from spectroscopic measurements and Judd-Ofelt calculations, our model shows that very high gain (>30 dB) is possible in short lengths (40-100 cm) of fiber. Given the very high quantum efficiency of the radiative transition in this glass, we show that bottlenecking and ESA should not have a significant impact on device performance. We also predict that devices made from this fiber should have a very high tolerance to the passive loss of the fiber 相似文献
3.
Yamada M. Shimizu M. Takeshita T. Okayasu M. Horiguchi M. Uehara S. Sugita E. 《Photonics Technology Letters, IEEE》1989,1(12):422-424
The performance of an Er3+-doped fiber amplifier pumped by 0.98 μm InGaAs laser diodes (LDs) is reported. By using a fiber with low Er3+ content and optimizing the fiber length, a maximum signal gain of 37.8 dB at 30-mW pump power was realized at a signal wavelength of 1.536 μm. A maximum gain coefficient of 1.9 dB/mW at 14 mW pump power was achieved. It was found that the fiber amplifier pumped by the 0.98-μm LDs is twice as efficient as that pumped by 1.48-μm LDs, from the viewpoint of both required fiber length and the attained gain 相似文献
4.
A theoretical model is developed for the laser-diode-pumped Tm3+-doped fiber amplifier, and a set of ordinary differential equations (ODEs) governing the dynamics of dual-wavelength pumping
scheme (1.4μ+1.56μ) based on the rate equations and propagation equations was established. The relationship between the spectra
gain and pump power was described and analyzed by numerically solving the ODEs. Spectral gain as a function of longitudinal
position along the fiber was given to optimize the fiber length; spectral gain per unit length, and fractional inversion were
used to explain the gain shift property of TDFA. The theoretical results agree well with the experimental data.
Received 28 March
Supported by China Scholarship Council, Natural Science Foundation of Shandong Province of China (grant no. Y2003G01 and Y2002G06),
Research Fund for the Doctoral Program of Higher Education of China (grant no. 2002022048 相似文献
5.
《Photonics Technology Letters, IEEE》1994,6(3):369-371
We demonstrate a simple method to produce high-energy pulses with peak powers up to 100 times their average power and with duration on the order of 1 μs using the synchronization of relaxation oscillations by drive current modulation of the intracavity pump laser diode. The forced sustained relaxation oscillations are shown to depend on wavelength, and the frequency locking curve exhibits a strong asymmetry with hysteresis behavior 相似文献
6.
Hamada M. Shimizu M. Okayasu M. Takeshita T. Horiguchi M. Tachikawa Y. Sugita E. 《Photonics Technology Letters, IEEE》1990,2(3):205-207
Measured noise characteristics of Er3+-doped optical fiber amplifiers pumped by 0.98- and 1.48-μm laser diodes (LDs) are reported. The noise figures estimated from the beat noise between signal and spontaneous emission are 3.2 dB for pumping by 0.98-μm LD and 4.1 dB for pumping by 1.48-μm LD. The beat noise between spontaneous emission components and the spontaneous shot noise for the 0.98-μm pumping are lower than those for the 1.48-μm pumping 相似文献
7.
The erbium-doped fiber amplifier noise figure spectrum and its evolution under various pumping regimes is analyzed. The analysis shows that noise figures in the range ±0.15 dB around the 3-dB quantum limit are possible within a spectral band of 50 nm. This demonstrates the possibility of quantum-limited amplification for broadband wavelength-division multiplexed (WDM) signals 相似文献
8.
A thorough investigation of Pr3+-doped fluoride fiber upconversion lasers at the blue, green, and red wavelengths has been conducted based on both numerical and analytical models. Many aspects of the blue laser system are studied including population inversion, pump absorption, and signal mode determination. The most important parameters in the blue laser are analyzed in detail. Based on the investigations, design optimization of the laser is discussed. Experimental results are also presented for the verification of the theoretical models 相似文献
9.
M. Wada K. Yoshino M. Yamada J. Temmyo 《Photonics Technology Letters, IEEE》1991,3(11):953-955
An investigation of epitaxial-layer structures has yielded narrow ridge waveguide structure lasers capable of coupling high optical power into single-mode fiber (SMF). An optical power of well over 60 mW in SMF was obtained for a 2- mu m-wide ridge waveguide laser with a guided separate-confinement-heterostructure (SCH) epitaxial structure. Calculated results indicate that the stringent limit imposed on 0.98- mu m wavelength detuning is relaxed for such high optical power coupled into a SMF. The 0.98- mu m strained-quantum-well lasers thus show considerable promise as a practical low-noise pumping source for Er-doped optical-fiber amplifiers.<> 相似文献
10.
Short high-concentration Yb3+-sensitized Er3+-doped fiber amplifiers are modeled and numerically investigated in the small-signal domain. Concentration quenching is included with a term quadratic in the concentration of excited Er3+ . We find that for fibers shorter than 1 m, the small-signal gain can be larger for sensitized fibers than for non-sensitized ones (31 dB gain vs. 22 dB at 5 cm). Without concentration quenching (e.g. for long fibers), Yb3+-free amplifiers have a higher small-signal gain. The achievable gain of the sensitized amplifier is independent of the pump laser wavelength, if the Yb-concentration is correspondingly optimized. However, restrictions on allowable Yb-concentrations imply that for a specific pump wavelength, a finite range of amplifiers lengths is suitable 相似文献
11.
Fukushima T. Matsumoto N. Nakayama H. Ikegami Y. Namegaya T. Kasukawa A. Shibata M. 《Photonics Technology Letters, IEEE》1993,5(9):963-965
Compressively strained 1.3-μm GaInAsP/InP multiple-quantum-well (MQW) ridge waveguide lasers were fabricated. Through optimizing the total well thickness, large bandwidth over 11 GHz was achieved, together with high quantum efficiency of about 0.48 W/A and high power output of 60 mW before rollover. The laser also showed less temperature sensitivity up to an elevated temperature of 85°C 相似文献
12.
Okayasu M. Takeshita T. Yamada M. Kogure O. Horiguchi M. Fukuda M. Kozen A. Oe K. Uehara S. 《Electronics letters》1989,25(23):1563-1565
High-power GaInAs strained quantum well lasers with an emission wavelength of 0.98 mu m, suitable for Er/sup 3+/-doped fibre amplifier pumping, have been fabricated. A threshold current of 15 mA and a peak output power as high as 85 mW have been obtained for the ridge waveguide structure with AR/HR facet coating. Highly efficient pumping for the 1.536 mu m signals has been confirmed.<> 相似文献
13.
Yamada M. Shimizu M. Ohishi Y. Temmyo J. Wada M. Kanamori T. Horiguchi M. Takahashi S. 《Photonics Technology Letters, IEEE》1992,4(9):994-996
A Pr3+-doped fluoride amplifier pumped by high-power 1.017-μm laser diode modules is demonstrated. Fiber-pigtail-type devices are used. A net gain of 15.1 dB is achieved for a 1.31-μm signal at a pump power of 160 mW 相似文献
14.
To explore the fundamental limits on performance at 1.3 μm, a model for Nd3+-doped fiber amplifiers which includes signal saturation and excited state absorption (ESA) at the signal wavelength has been constructed. Ignoring ESA, the difference in pump efficiency between a low-performance and a high-performance glass host is ≈60%, indicating that ESA is the critical parameter distinguishing experimental results reported for different materials. The pump efficiency for a linear Nd3+ amplifier is an order of magnitude less than for an Er3+ amplifier without ESA and degrades still further with its inclusion. Applications as power amplifiers are more promising, because, in principle, high power conversion efficiencies can be obtained 相似文献
15.
Le Flohic M. Franchois P.-L. Allain J.-Y. Sanchez F. Stephan G.M. 《Quantum Electronics, IEEE Journal of》1991,27(7):1910-1921
The two-stage process of the transient buildup of emission in Nd 4+-doped fiber lasers is described both experimentally and theoretically. After switching on the pump, spontaneous emission increases first until the gain becomes sufficient to compensate for the cavity losses; the laser field then develops and reaches the steady state after more or less regular oscillations. During this second stage, an almost chaotic spiking is obtained either for high pumping rates and/or at low temperatures. The whole set of these dynamical scenarios is not described under the usual assumptions of uniform cavity losses over the whole field spectrum and of pure homogeneous broadening for the transition line, but rather a modified form of the Maxwell-Bloch equations which retains some frequency dependence for the losses in the cavity and the inhomogeneous broadening as well is proposed 相似文献
16.
Gokhale M.R. Dries J.C. Studenkov P.V. Forrest S.R. Garbuzov D.Z. 《Quantum Electronics, IEEE Journal of》1997,33(12):2266-2276
We describe the design and experimental results for high-power, high-efficiency, low threshold current, 0.98-μm wavelength, broadened waveguide (BW) aluminum-free InGaAs-(In)GaAs(P)-InGaP lasers. The decrease in the internal losses with an increase in the width of the waveguide layer for a separate-confinement heterostructure multiple-quantum-well (SCW-MQW) structure is attributed to lower free-carrier absorption due to the reduced overlap of the optical mode with the highly doped cladding regions. The BW lasers grown with both InGaAsP and GaAs waveguides show lower internal losses and similar threshold currents than those designed for an optimum optical confinement factor within the QW region. We report a record-low internal loss of 1.8±0.2 cm-2 for (In)GaAs(P)-InGaP lasers grown by gas-source molecular beam epitaxy (GSMBE). The temperature dependence of internal loss suggests that optical loss from free-carrier absorption in the waveguide dominates at T>40°C, while near room temperature, the residual loss is attributed to scattering and free-carrier absorption in the QW's. The relative insensitivity of internal loss near room temperature has enabled the use of a simplified InGaAs-GaAs-InGaP BW structure to achieve very high CW and quasi-CW (QCW) power operation. We report the highest CW output power of 6.8 W for a GaAs-InGaP laser, and the highest quasi-continuous output power of 13.3 W measured for a single 100-μm-wide aperture, 0.8-0.98-μm wavelength Al-free laser diode grown by GSMBE 相似文献
17.
Metal-clad ridge waveguide (MCRW), double quantum well, separately confined heterostrucuture (DQW-SCH) lasers have been fabricated having continuous-wave (CW) threshold currents of 10?12 mA and external differential quantum efficiencies of 41?46% per uncoated facet. Light/current characteristics are linear to >70 mW, and zero-order lateral mode operation was measured at 56 mW. The CW burn-off power density is nearly double the best previously reported value. 相似文献
18.
A high capacity noncoherent FSK lightwave field experiment using Er3+-doped fiber optical amplifiers
Fishman D.A. Nagel J.A. Cline T.W. Tench R.E. Pleiss T.C. Miller T. Coult D.G. Milbrodt M.A. Yeates P.D. Chraplyvy A. Tkach R. Piccirilli A.B. Simpson J.R. Miller C.M. 《Photonics Technology Letters, IEEE》1990,2(9):662-664
19.
Kovsh A.R. Wang J.S. Hsiao R.S. Chen L.P. Livshits D.A. Lin G. Ustinov V.M. Chi J.Y. 《Electronics letters》2003,39(24):1726-1728
High-power narrow ridge waveguide lasers emitting with a wavelength around 1.3 /spl mu/m were realised with a single In/sub 0.36/GaAsN/sub 0.022/ quantum well with GaAs barriers. A narrow vertical far-field angle of 35/spl deg/ was obtained. Single lateral mode continuous-wave operation with slope efficiency of 0.57 W/A, series resistance of 2.6 /spl Omega/, and kink-free output power of 210 mW was achieved. 相似文献
20.
An investigation of a Pr3+-doped Al2O3 -SiO2 glass fiber is described. The basic material parameters like fluorescence lifetime and stimulated emission cross section, measured around 1048 nm, where the fiber has a strong emission band, are discussed. The pump source was a Rh6G dye laser at 590 nm. Continuous wave (CW,) operation with a slope efficiency of 26% and a pump threshold of 1.2 mW was obtained. The Q-switched operation, yielding a repetition rate up to 10 kHz with a maximum peak power of 30 W and a minimum pulsewidth of 25 ns, is described 相似文献