Field Transmission using Fiber Bragg Grating-based Dispersion Compensating Modules with Continuous Response over the Full C-band
Fiber Bragg grating-based dispersion compensating modules with continuous response over the full C-band are demonstrated. Group delay characteristics are analysed and modules are used in 10-Gbit/s and 40-Gbit/s field experiments over 820 km installed fiber.
16 x 10 Gb/s WDM transmission over 840-km SMF using eleven broad-band chirped fiber gratings
We demonstrate wavelength-division-multiplexed transmission of 16 10-Gb/s nonreturn-to-zero channels with 50-GHz spacing over 840 km of conventional single-mode fiber (SMF), or 14 times the 10-Gb/s dispersion limit, using a total of eleven chirped fiber gratings for dispersion compensation. Each grating has a nominal dispersion of -1330 ps/nm km for compensating 80 km of SMF and a bandwidth of 6.5 nm, and one grating has additional dispersion slope compensation of -35 ps/nm/sup 2/ equivalent to 480 km of SMF. The large number of closely spaced wavelengths and long transmission distance significantly stress the wavelength uniformity, bandwidth, and cascadability of the fiber gratings.
THE PERFORMANCE OF STEADY DETONATION ENGINES
Propulsion systems driven by steady normal detonations are studied. The practical di‐culties associated with stabilizing a detonation wave are highlighted. The requirement on the freestream total enthalpy is considered in parallel with efiects such as condensation or auto-ignition of the fuel-air mixture and limitations associated with fuel sensitivity to detonation. A criterion for detonation stabilization is formulated and applied to an analytical treatment of a detonation ramjet and a detonation turbojet, which are the respective analogs of the ramjet and the turbojet using detonative combustion. The performance of these engines is evaluated and compared to the ideal ramjet and turbojet models for hydrogen and JP10. A limitation is placed on the maximum total temperature allowed in the combustor, based on material considerations. The results show that steady detonation engines have a small thrust-producing range, due to the requirements for detonation stabilization. Their performance is always lower than that of the conventional ramjet and turbojet because of the total pressure loss across the detonation.