1.12 Tb/s superchannel coherent PM-QPSK InP transmitter photonic integrated circuit (PIC).

In this work, a 10-wavelength, polarization-multiplexed, monolithically integrated InP coherent QPSK transmitter PIC is demonstrated to operate at 112 Gb/sec per wavelength and total chip superchannel bandwidth of 1.12 Tb/s. This demonstration suggests that increasing data capacity to multi-Tb/s per chip is possible and likely in the future.

Parallel free-space optical interconnect based on arrays of vertical-cavity lasers and detectors with monolithic microlenses.

We investigate the use of low-threshold 980-nm vertical-cavity surface-emitting lasers for free-space optical interconnects. The vertical-cavity surface-emitting lasers and backilluminated detectors are monolithically integrated with microlenses on the back sides of the growth substrates to eliminate the necessity of external optics. With a channel pitch of 250 mum, an interconnect length between boards of the order of 5 to 10 mm with a ?50-mum lateral alignment tolerance can be achieved without external relay optics. The complete link is modeled to predict the system's efficiency and maximum bit rate. Data transmission at 500 Mbits/s per channel is demonstrated. The data rate was limited by parasitics, not the inherent bandwidth of the laser diodes.

Effect of heparin on the porcine lymphocyte chromatin--II. Comparative study of sedimentation of chromatin DNA and isolated DNA.

1. Sedimentation of chromatin DNA and isolated deproteinized DNA was compared in neutral and alkaline sucrose density gradients after incubation of chromatin or DNA with various concentrations of heparin. 2. Irrespective of the molecular weight of DNA, an increase in the sedimentation constant of DNA was found with increasing concentration of the polyanion employed.

The effect of heparin on the porcine lymphocyte chromatin--I. The comparative study of DNA in different chromatin fractions.

1. Porcine lymphocyte chromatin in the solution of 0.15 M NaCl + 0.01 M Tris, pH 7 treated with heparin liberated 30% protein and 7.5% DNA to the supernatant. 2. DNA from the supernatant and the pellet fractions as well as from control chromatin were isolated in identical conditions. 3. No significant changes were observed in spectral properties and melting points in SSC of comparable DNA specimens. 4. It was noted, however, that DNA of the supernatant is subject to denaturation in the process of isolation, which, apart from the difference in protein composition of the supernatant and the pellet fractions, suggests different chromatin structure of these fractions.