1.55-mu m InGaAs/InGaAlAs MQW vertical-cavity surface-emitting lasers with InGaAlAs/InP distributed Bragg reflectors

High-performance InGaAs/InGaAlAs multiple-quantum-well vertical-cavity surface-emitting lasers (VCSELs) with lnGaAlAs/InP distributed Bragg reflectors are proposed for operation at the wavelength of 1.55 mum. The lasers have good heat diffusion characteristic, large index contrast in DBRs, and weak temperature sensitivity. They could be fabricated either by metal-organic chemical vapor deposition (MOCVD) or by molecular beam epitaxy (MBE) growth. The laser light-current characteristics indicate that a suitable reflectivity of the DBR on the light output side in a laser makes its output power increase greatly and its lasing threshold current reduce significantly, and that a small VCSEL could output the power around its maximum for the output mirror at the reflectivity varying in a broader range than a large VCSEL does. (C) 2004 Elsevier Ltd. All rights reserved.

High-efficiency reflective diffraction gratings in fused silica as (de)multiplexers at 1.55 mu m for dense wavelength division multiplexing application

We describe high-efficiency, high-dispersion reflection gratings fabricated in bulk fused Silica illuminated by incident lights in the C + L bands as (de)multiplexers for dense wavelength division multiplexing (DWDM) application. Based on the phenomenon of total internal reflection, gratings with optimized profile parameters exhibit diffraction efficiencies of more than 90% under TM- and TE-polarized incident lights for 101-nm spectral bandwidths (1520-1620 nm) and can reach an efficiency of greater than 97% for both polarizations at a wavelength of 1550 nm. Without loss of metal absorption, without coating of dielectric film layers, and independent of tooth shape, this new kind of grating should be of great interest for DWDM application. (C) 2005 Optical Society of America.

Spectroscopic properties of Er3+-doped tellurite glass for 1.55 mu m optical amplifier

Er3+-doped TeO2-BaO (Li2O, Na2O)-La2O3 tellurite glass system was prepared and their density, characteristic temperatures and optical properties were determined and investigated. For the TeO2-BaO-La2O3-Er2O3 system, composition with 10 mol% BaO presented the highest thermal stability and good infrared transmittance. Intense and broad 1.53 mu m infrared fluorescence were observed under 977 nm diode laser excitation and the most full width at half-maximum (FWHM) is similar to 60nm. According to absorption spectrum, we calculated the optical parameters by means of Judd-Ofelt and McCumber theory such as the fluorescence lifetimes which are about 2.72-3.25 ms and the maximum emission cross-sections which are similar to 1.0pm(2) at 1.531 mu m. The sigma(e) x FWHM value of composition with 10 mol% BaO for gain bandwidth is similar to 600 exceeding those in silicon and phosphate glasses. Our results indicated this kind of tellurite glasses could be used as an ideal host glass for optical amplifier. (c) 2005 Elsevier B.V. All rights reserved.

Effect of La3+ on microwave dielectric properties of (Pb0.45Ca0.55) (Fe0.5Nb0.5)O-3 ceramics

In this work, microwave dielectric properties of A-site substitution by La3+ in (Pb0.45Ca0.55) (Fe0.5Nb0.5) 03 system were investigated. Microwave dielectric properties of A-site charge unbalance substitution of [(Pb0.45Ca0.55)(1-x) La-x] (Fe0.5Nb0.5)O-3(+) (P45CLFN) were improved because the solid solution of small amount of surplus La3+ with (Pb, Ca)(2+) could eliminate oxygen vacancies, and the formation of secondary phase (pyrochlore) was also caused by surplus La3+. The decreasing of dielectric constant with the increase of La3+ content is due to the formation of pyrochlore. The grain size is changed slightly and Q(f) values (7000 similar to 7300 GHz) are almost unchanged at x = 0.02 similar to 0.10, but the temperature coefficient of resonant frequency (TCF) are increased and changed from negative to positive. TCF is zero at x 0.075 with Q(f) = 7267 GHz and K = 89. TCF of all specimens are within +/- 5 x 10(-6)degrees C-1.

围圈养鱼对浮游动物多样性的影响

1993—1994年在保安湖主体湖区开展围圈养殖草鱼对浮游生物多样性影响的研究，包括围圈内外浮游动物种类组成、密度、生物量和多样性指数的季节变化等。分析表明，围圈内共有常见浮游动物64种，围圈外共有常见浮游动物55种。围圈内外浮游动物的年平均密度分别为3738和3196ind/L，年平均生物量分别为0.8177和0.8135mg/L，年平均多样性指数分别为3.3808和2.9717。研究结果表明：围圈养殖草食性鱼类对浮游动物现存量以及多样性指数无显著影响.

1.55微米掩埋异质结DFB激光器的研制

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

光通信用1.55微米InGaAsP/InP DH激光器中的0.95微米发光和俄歇复合

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

长波长（1.3-1.55μm）自组织InGaAs/GaAs量子点的分子束外延生长

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

Si 基1.55 微米RCE 探测器的材料生长与器件制作

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

1.3-1.55 m GaInNAs 多量子阱共振腔增强型探测器

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

GaAs 基1.3-1.55μm GaInNAs(Sb)量子阱及激光器、探测器的分子束外延生长

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

GaAs 基1.55μm 波段InAs 自组织量子分子束外延生长

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

GaAs 基1.55 μm GaInNAs(Sb)、异变InGaAs 量子阱材料与激光器

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z