共查询到20条相似文献,搜索用时 31 毫秒
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A complex-coupled DFB Laser with sampled grating has been designed and fabricated. The key concepts of the approach are to utilize the +1st order reflection of the sampled grating for laser single mode operation, and use a conventional holographic exposure combined with the usual photolithography to fabricate the sampled grating. The typical threshold current of the sampled grating based DFB laser is 25mA, and the optical output is about 10mW at the injected current of 100mA. The lasing wavelength of the device is 1.5385μm, which is the +1st order wavelength of the sampled grating. 相似文献
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A complex-coupled DFB laser with sampled grating has been designed and fabricated. The method uses the + 1 st order reflection of the sampled grating for laser single-mode operation. The typical threshold current of the sampled grating based DFB laser is 25 mA, and the optical output is about 10 mW at the injected current of 100 mA. The lasing wavelength of the device is 1.5385μm, which is the +1 st order wavelength of the sampled grating. 相似文献
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Ligeret V. Holleville D. Perrin S. Bansropun S. Lecomte M. Parillaud O. Calligaro M. Krakowski M. Dimarcq N. 《Electronics letters》2008,44(13):804-806
Low linewidths for Al-free active region distributed feedback lasers using a self-heterodyne measurement method (minimum beat width of 0.8 MHz at 20 mW and 12 C, 1.2 MHz at 852.12 nm 35 mW and 36 C) are demonstrated. Singlemode emission was achieved at 852.12 nm corresponding to the D2 caesium transition, with an optical output power of 35 mW at 140 mA under CW operation. Finally, the saturation spectra of caesium atoms with the DFB laser diode was recorded with a resolution close to the natural linewidth. 相似文献
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Twu Y. Karlicek R.F. Wynn J.D. Green C.A. Roxlo C.B. Wang S.J. Dutta N.K. 《Electronics letters》1989,25(16):1045-1046
The performance characteristics of quarter-wave shifted GaInAsP distributed feedback lasers emitting near 1.3 mu m are described. The quarter-wave shifted grating is fabricated on a substrate using the double-exposure holographic technique. The low reflectivity required for this quarter-wave shifted DFB laser is obtained using buried facets at both ends of the laser. The lasers have threshold current of 30 mA, quantum efficiency of 0.18 mW/mA/facet, bandwidth of 11.5 GHz at 10 mW and 10 dB chirp width of 2.5 AA under 40 mA modulation current at 5 Gbit/s.<> 相似文献
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Asonen H. Nappi J. Ovtchinnikov A. Savolainen P. Zhang G. Ries R. Pessa M. 《Photonics Technology Letters, IEEE》1993,5(6):589-591
The authors discuss the fabrication and characteristics of high-power (P CW=430 mW) InGaAs/InGaAsP/InGaP ridge waveguide lasers emitting at λ=0.98 μm, which is the optimum wavelength for pumping erbium-doped fiber amplifiers. In the past, high-power operation of Al-free pump lasers has been limited to 150 mW because of catastrophic optical damage of the mirror facet. This problem has been largely removed by increasing the spot size of the laser with the aid of an improved waveguide design. As a result, Al-free lasers can now achieve a maximum power comparable to the conventional GaAlAs-based pump lasers for λ=0.98 μm 相似文献
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Cao H.L. Luo Y. Nakano Y. Tada K. Dobashi M. Hosomatsu H. 《Photonics Technology Letters, IEEE》1992,4(10):1099-1102
Grating duty factor strongly affects the performance of gain-coupled (GC) distributed feedback (DFB) laser diodes with an absorptive grating. Through numerical analysis the authors have found an optimum value in the duty factor for their low threshold operation. The minimum threshold gain achievable at this optimum duty factor is found to be almost independent of the order of the grating. According to this prediction, the authors have fabricated GaAlAs/GaAs GC DFB lasers with a third-order absorptive grating where the grating duty factor has been made close to the theoretical optimum value. In 200-μm-long devices with both facets as-cleaved, low CW threshold current of 25 mA, external efficiency of 0.5 mW/mA, and SMSR as high as 45 dB have been obtained, which is qualitatively consistent with the analysis. High yield of single mode oscillation seems to be the result of the gain coupling 相似文献
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Tsang W.T. Choa F.S. Wu M.C. Chen Y.K. Logan R.A. Sergent A.M. Burrus C.A. 《Photonics Technology Letters, IEEE》1992,4(3):212-215
Successful operation of long-wavelength InGaAsP low-threshold-current gain-coupled DFB lasers was demonstrated by using an InGaAsP quaternary grating that absorbs the DFB (distributed feedback) emission. The amount of gain (loss)-coupling is controlled by the composition (bandgap) and thickness of the grating quaternary and the InP-spacer layer between the grating and the active layer. With optimally designed lasers, CW (continuous-wave) threshold currents were 10-15 mA (250-μm cavity, as-cleaved), slope efficiency was ~0.4 mW/mA (both facets) and SMSR (side-mode suppression ratio) was as high as 52 dB. The laser operated in the same DFB mode with SMSR staying ~50 dB throughout the entire current range. At 100°C, the CW threshold current stayed low, ~50 mA, and SMSR was ~40 dB. Results also indicate that the presence of gain-coupling removes the degeneracy in lasing wavelength 相似文献
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Hansmann S. Burkhard H. Dahlhof K. Schlapp W. Losch R. Nickel H. Hillmer H. 《Lightwave Technology, Journal of》1992,10(5):620-625
Optical waveguiding in an InGaAs/GaAs strained-layer distributed feedback (DFB) quantum well laser is investigated using the one-dimensional shooting method presented. The numerical approach is used to optimize the waveguide geometry and to calculate the corrugation period and the coupling factor for the integrated Bragg grating. The quantum well DFB structure designed according to the numerical calculations for an emission wavelength of 982 nm was realized for the first time entirely by molecular beam epitaxy (MBE) growth. Thus, side-mode suppression ratios of 49 dB, threshold currents of 7 mA and quantum efficiencies of 0.4 mW/mA were achieved 相似文献
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Stable in-phase lateral- and single-longitudinal-mode operation up to four times the threshold (P o~100 mW) was achieved in a five-element 1.5-μm-wavelength Ga0.3In0.7As/GaInAsP/InP compressive strained MQW grating filter laser array. The threshold current and external differential quantum efficiency under pulsed condition were 330 mA (emitter width of 18 μm, active region length of 480 μm) and 17%, respectively 相似文献
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Littrow型光栅外腔半导体激光器的输出特性分析 总被引:1,自引:0,他引:1
在讨论光栅外腔半导体激光器理论的基础上.对影响Littrow型光栅外腔半导体激光器输出功率和线宽压窄的各种因素进行了数值模拟分析.研制了单纵模高质量激光输出的Littrow型光栅外腔半导体激光器,在工作电流为400 mA时,连续输出功率达到180 mW,线宽优于1 MHz. 相似文献
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Martin R.D. Forouhar S. Keo S. Lang R.J. Hunsperger R.G. Tiberio R.C. Chapman P.F. 《Photonics Technology Letters, IEEE》1995,7(3):244-246
Single-mode distributed feedback (DFB) laser diodes typically require a two-step epitaxial growth or use of a corrugated substrate. We demonstrate InGaAs-GaAs-AlGaAs DFB lasers fabricated from a single epitaxial growth using lateral evanescent coupling of the optical field to a surface grating etched along the sides of the ridge. A CW threshold current of 25 mA and external quantum efficiency of 0.48 mW/mA per facet were measured for a 1 mm cavity length device with anti-reflection coated facets. Single-mode output powers as high as 11 mW per facet at 935 nm wavelength were attained. A coupling coefficient of at least 5.8 cm-1 was calculated from the subthreshold spectrum taking into account the 2% residual facet reflectivity 相似文献
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Fallahi M. Dion M. Chatenoud F. Templeton I.M. McGreer K.A. Champion G. Barber R. 《Electronics letters》1993,29(16):1412-1414
Reports the fabrication and low divergence operation of an electrically pumped circular grating surface emitting DBR laser on an InGaAs/GaAs SQW structure. A threshold current below 85 mA, output power of more than 20 mW and a divergence of less than 1 degrees FWHM were obtained.<> 相似文献
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A gain-coupled (GC) strained-layer (SL) multi-quantum-well (MQW) distributed-feedback (DFB) laser with a metallized surface grating and a substantially simplified fabrication process made by single-step epitaxy without corrugation overgrowth is described. The complex coupling coefficient can be adjusted by the contact metallization. Room-temperature single-mode continuous-wave (CW) operation with a threshold current of 22 mA, an output power of 20 mW, and a linewidth of 2.5 MHz is demonstrated 相似文献
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Su Y.-K. Li W.-L. Chang S.-J. Chang C.S. Tsai C.S. 《Electron Devices, IEEE Transactions on》1998,45(4):763-767
We have grown high-performance AlGaInP/GaInP visible (670 mn) strained quantum well lasers by low-pressure metalorganic chemical vapor deposition. With AlInP cladding layer, a high-power AlGaInP/GaInP visible laser diode is achieved. Its threshold current is about 30 mA. The output power of this laser diode can maintain, at least, at 32 mW under continuous-wave (CW) operation at room temperature. High slope efficiency (0.8 mW/mA) and differential quantum efficiency (0.87) can be achieved. To improve beam quality, AlGaInP/GaInP visible lasers with and without depressed index cladding layer are theoretically and experimentally studied. From experimental results, the transverse beam divergence can be reduced from 41.4° to 26.2° while maintaining a low threshold current (from 36 mA to 46 mA). By using the transfer matrix method, our theoretical calculations are in good agreement with the experimental results 相似文献
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We report on the material growth and fabrication of high-performance 980-nm strained quantum-well lasers employing a hybrid material system consisting of an Al-free InGaAs-InGaAsP active region and AlGaAs cladding layers. The use of AlGaAs cladding instead of InGaP provides potential advantages in flexibility of laser design, simple epitaxial growth, and improvement of surface morphology and laser performance. The as-grown InGaAs-InGaAsP(1.6 eV)-AlGaAs(1.95 eV) lasers achieve a low threshold current density of 150 A/cm2 (at a cavity length of 1500 μm), internal quantum efficiency of ~95%, and low internal loss of 1.8 cm-1. Both broad-area and ridge-waveguide laser devices are fabricated. For 100-μm-wide stripe lasers with a cavity length of 800 μm, a slope efficiency of 1.05 W/A and a characteristic temperature coefficient (T0) of 230 K are achieved. The lifetime test demonstrates a reliable performance. The comparison with our fabricated InGaAs-InGaAsP(1.6 eV)-AlGaAs(1.87 eV) lasers and Al-free InGaAs-InGaAsP (1.6 eV)-InGaP lasers are also given and discussed. The selective etching between AlGaAs and InGaAsP is successfully used for the formation of a ridge-waveguide structure. For 4-μm-wide ridge-waveguide laser devices, a maximum output power of 350 mW is achieved. The fundamental mode output power can be up to 190 mW with a slope efficiency as high as 0.94 W/A 相似文献
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Chih-Wei Hu Feng-Ming Lee Kun-Fu Huang Meng-Chyi Wu Chia-Lung Tsai Yin-Hsun Huang Lin C.-C. 《Photonics Technology Letters, IEEE》2006,18(14):1551-1553
In this letter, we proposed an alternate method by using the Fe-doped InGaAsP-InP hybrid grating layers to fabricate the 1.3-/spl mu/m current-blocking-grating complex-coupled distributed-feedback (CBG CC-DFB) laser diodes (LDs) grown by metal-organic chemical vapor deposition (MOCVD). By combining the Fe-doped InGaAsP-InP grating layers, the CBG CC-DFB LDs can provide high optical DFB coupling coefficient and high current confining ability. Moreover, the current aperture in the lateral direction can be easily controlled by the self-aligned MOCVD regrowth process. Therefore, the manufacture of CBG CC-DFB buried heterostructure LDs is easy as the ridge-waveguide LDs. The LDs exhibit a low threshold current of 5.3 mA, a high slope efficiency of 0.42 mW/mA, and a stable single mode with a high sidemode suppression ratio of /spl sim/42 dB at two times the threshold (10.5 mA). Even at high temperatures, these LDs still have an extremely low threshold current of 15.8 mA at 90/spl deg/ and a small variation in slope efficient of only -1 dB at the temperatures between 20/spl deg/ and 80/spl deg/. Furthermore, these LDs show a high-speed characteristic of more than 11.8 GHz at 20/spl deg/, which are suitable for 10-Gb/s Ethernet and OC-192 applications. 相似文献