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Abstract: A reverse dispersion fiber (RDF) with depressed core-index profile has been developed successfully by using plasma chemical vapor deposition (PCVD) process. The fabricated RDF has a core-effective-area of 45μm2, a dispersion of −19.65ps/nm/km and a dispersion slope of −0.132ps/nm2/km while maintaining the low bending induced attenuation and low PMD value. The dispersion-managed pairs, which consisted of RDF and non-zero dispersion shifted fiber with ultra large effective core-area (ULAF), have the ultra low dispersion slope of less than 0.006ps/nm2/km at the wavelength range of 1530–1625nm, and the largest dispersion value is lower than 0.2ps/nm/km. Moreover, the attenuation characteristic also shows a remarkable flatness over the broadband wavelength, the attenuation at 1550nm is only 0.224dB/km. The dispersion-managed pairs are suitable for large capacity, high bit-rate long-haul wavelength division multiplexing (WDM) transmission system without using dispersion compensation mode. [Copyright &y& Elsevier]

A non-zero dispersion-shifted fiber based on a depressed core-index for the large capacities and high bit-rate transmission system is designed and fabricated. The fiber with this structure has the effective-core-area (Aeff) of more than 100 μm2 and dispersion slope of less than 0.065 ps/nm2/km at 1.55 μm wavelength simultaneously while maintaining the good bending loss. The zero-dispersion wavelength is shifted to lower than 1430 nm, so this fiber can be used on not only the conventional C-band (1530–1565 nm), but also S-band (1460–1530 nm) and L-band (1565–1625 nm) for dense wavelength division multiplexing. In addition, the designed fiber has a low polarization mode dispersion of about 0.04 ps/√ of km and an attenuation of around 0.21 dB/km at 1550 nm, the splice loss with conventional single mode fiber is less than 0.11 dB. [Copyright &y& Elsevier]

Abstract: We report on normal incidence p–i–n heterojunction photodiodes operating in the near-infrared region and realized in pure germanium on planar silicon substrate. The diodes were fabricated by ultrahigh vacuum chemical vapor deposition at 600°C without thermal annealing and allowing the integration with standard silicon processes. Due to the 0.14% residual tensile strain generated by the thermal expansion mismatch between Ge and Si, an efficiency enhancement of nearly 3-fold at 1.55μm and the absorption edge shifting to longer wavelength of about 40nm are achieved in the epitaxial Ge films. The diode with a responsivity of 0.23A/W at 1.55μm wavelength and a bulk dark current density of 10mA/cm2 is demonstrated. These diodes with high performances and full compatibility with the CMOS processes enable monolithically integrating microphotonics and microelectronics on the same chip. [Copyright &y& Elsevier]