Photonics Integrations Enabling High-end Applications Of Inp In Optical Data Transmissions

We present here results from a uniquely designed InP modulator chip combined with advanced packaging concepts, which enables high-end applications in optical data communications. An electroabsorption (EA) modulator, with a strained InGaAsP or InGaAlAs multiple quantum well structure, is monolithically integrated with a semiconductor optical amplifier. This design offers broad wavelength tunability while maintaining high extinction ratio, high optical output power, and high dispersion tolerance. The amplified EA modulator chip is co-packaged with a distributed feed back (DFB) laser ensuring separate optimization of the laser and modulator sections. The optical isolator, placed between the laser and modulator, completely eliminates adiabatic chirp. This Telcordia-qualified laser integrated modulator platform enables superior performance previously not thought possible for InP absorption based modulators. 11 dB of dynamic extinction ratio, 5dBm of modulated output power, and ±1200ps/nm or +1600ps/nm dispersion tolerance can be simultaneously achieved in un-amplified 10Gb/s data transmission. Full C-band tunability using a single device is also demonstrated with the LIM module. Extensive simulations and transmission system evaluations shows that with the controllable chirp, the cost-effective LIM performs as well as a Mach-Zehnder modulator in dispersion managed and amplified long-haul WDM systems. Lastly, the first uncooled 10Gb/s long-reach operation at 1550nm was demonstrated with LIM packages. Using a simple control algorithm, a constant modulated output power of IdBm with less than IdB dispersion penalty over 1600ps/nm single mode fiber is achieved in an 80 degrees environmental temperature range without any module temperature control. Utilizing the Al-based material system, also allows a reduced variation of the extinction ratio.6013Kaminow, I.P., Koch, T.L., (1997) Optical Fiber Telecommunications IIIA, , San Diego CA: Academic PressChoi, W., Bond, A.E., Kim, J., Zhang, J., Jambunathan, R., Foulk, H., O'Brien, S., Cao, H., Low insertion loss and low dispersion penalty InGaAsP quantum well high speed electroabsorption modulators (2002) IEEE Journal of Lightwave Technologies, 20, pp. 2052-2056Choi, W., Frateschi, N., Zhang, J., Gebretsadik, H., Jambunathan, R., Bond, A.E., Van Norman, J., Wanamaker, C., Full C-band tunable high fiber output power electroabsorption modulator integrated with semiconductor optical amplifier (2003) Electronics Letters, 39, p. 1271. , 2003Zhang, L., Cao, X.D., Long haul transmission using electro-absorption modulators (2002) Technical Proceeding of NFOEC'2002, p. 1204. , paper P447www.vpiphotonics.comMikhailov, V., Killey, R.I., Prat, J., Bayvel, P., Limitation to WDM transmission distance due to cross-phase modulation induced spectral broadening in dispersion compensated standard fiber systems (1999) IEEE Photon. Technol. Lett., 11, pp. 994-996Zhang, J., Frateschi, N., Choi, W., Gebretsadik, H., Jambunathan, R., Bond, A.E., A laser integrated modulator module for uncooled, 10Gbit/s 1550 nm long reach data transmission (2003) Electronics Letters, 39, pp. 1841-1842Frateschi, N.C., Zhang, J., Choi, W.J., Gebretsadik, H., Jambunathan, R., Bond, A.E., High performance uncooled C-band, 10 Gb/s InGaAlAs MQW electro-absorption modulator integrated to Semiconductor Amplifier in Laser integrated modules (2004) Electronics Letters, 40, pp. 140-141. , JanFrateschi, N.C., Zhang, J., Jambunathan, R., Choi, W.J., Ebert, C., Bond, A.E., Long reach uncooled performance of 10 Gb/s Laser integrated modules with InGaAlAs/InP and InGaAsP/InP MQW electroabsorption modulators monolithically integrated with Semiconductor Amplifiers IEEE Photon. Technol. Lett., 17, pp. 1378-138

Biochemical changes during seed development in sorghum (Sorghum bicolor)

Grain dry-weight accumulation and contents of soluble sugars, starch, protein, fat and ash were investigated in developing grains of eight cultivars. In the high-lysine mutant P721 and the high-lysine Ethiopian lines IS11167 and IS11758, contents of starch were relatively low and those of protein relatively high, suggesting a possible mechanism for protein accumulation at the expense of starch accumulation. RY49, also from Ethiopia, had a comparatively high rate of protein accumulation at various phases of maturation. Fat content tended to increase for up to 28 days after flowering and the accumulation rate was highest in RY49 and IS1116

Rapid Methods for Estimating Protein and Lysine in Sorghum (Sorghum bicolor (L.) Moench).

Sorghum (Sorghum bicolor (L.) Moench) samples were analyzed for protein by the Technicon auto analyzer (TAA) method, and the results were compared with the micro-Kjeldahl method. The TAA method was highly and significantly correlated (r = 0.997**) with the micro-Kjeldahl method, and the results were found to be highly reliable for routine screening of samples. Lysine was estimated by the rapid dye-binding capacity (DBC) procedure and was determined using an amino-acid analyzer. The results of the DBC procedure, when expressed as a ratio with respect to the protein content, were highly and positively correlated (r = 0.933**) with the amino-acid analyzer values. The rapid procedures of TAA and DBC were observed to give reliable estimates of protein and lysine content, respectively, and are recommended when large numbers of sorghum samples are to be analyzed

Changes in carbohydrates, amino acids and proteins in developing seed of chickpea

Developing seeds of chickpea cultivars G-130, L-550 and 850-3/27 grown under field conditions were sampled at different stages of maturity and analysed for soluble sugars, starch, soluble nitrogen, protein nitrogen and amino acids. Fr. wt of seeds of all three cultivars decreased after 28 days of flowering while the dry wt continued to increase. Rapid starch accumulation was observed between 14 and 28 days after flowering. Starch as per cent of seed dry wt started to decrease after 28 days, while starch per seed increased till maturity. The percentage of salt-soluble proteins decreased with maturation of seed. The electrophoretic pattern revealed that deposition of seed storage protein in cotyledons occurred 14 days after flowering. Most of the biochemical activity apparently occurred between 14 and 28 days after flowerin

Textural Properties of Sorghum Dough

Textural properties of dough prepared from the flours of eight sorghum cultivars were evaluated subjectively and also measured using a back-extrusion cell in an Instron Food Testing Instrument. The force and energy required for the extrusion of good quality cohesive dough were high. A poor quality dough was compressed into the cell without extrusion. The influence of flour-water-soluble components on dough conhesiveness are discusse

Nutritional quality evaluation of newly developed high-protein genotypes of pigeonpea (Cajanus cajan)

Two high-protein genotypes of pigeonpea (Cajanus cajan L), HPL 8 and HPL 40, were analysed for their nutritional quality characteristics, and the results were compared with those of normal-protein genotypes (C 11 and ICPL 211). The protein content of the high-protein genotypes was higher on average by nearly 20% but their starch content, the principal constituent of the seed, was lower by about 8%. The higher fraction (about 7%) of globulin, the major storage protein, was associated with a lower glutelin fraction in the high-protein genotypes. The amino acid composition (g per 100 g protein) of the high-protein genotypes was comparable with those of the normal-protein genotypes. However, the sulphur-containing amino acids methionine and cystine were noticeably higher (about 25%) in high-protein genotypes when results were expressed in g per 100 g sample. No large differences in true protein digestibility, biological value and net protein utilisation were observed between HP and NP genotypes. True protein digestibility was significantly increased by cooking in both whole-seed and dhal samples. The values for utilisable protein were considerably higher in high-protein genotypes, suggesting their superiority from the nutritional point of view

Evaluation of Protein Quality of Sorghum [Sorghum bicolor (L.) Moench]

Grain protein content varied from 6.8% to 19.6% in eight sorghum cultivars comprising land races, hybrids, and local cultivars. Amino acid contents and distribution of Landry and Moreaux protein fractions in grains were studied. Two Ethiopian land races had higher concentrations of lysine and threonine, as well as cystine, isoleucine, and tyrosine. Fraction I, comprising albumin-globulin including non-protein nitrogen, and fraction V (glutelin) together constituted about 41-55% of the protein in the eight sorghum cultivars. Variation in fraction II (prolamin) and fraction III (cross-linked prolamin) contents was observed among the cultivars. To elucidate the pattern of synthesis of protein fractions in grain, studies were made at different grain maturity periods, using one cultivar. Fraction I synthesis was initiated at 7 days after anthesis. Prolamin increased from 14 to 28 days and declined toward maturity. Glutelin did not change beyond 14 days after anthesis until maturit