All-optical 2R regeneration using passive saturable absorption

This paper reports on the regenerative properties and efficiency of an all-optical 2R regenerator based on a tandem of saturable absorber (SA) chips. A new SA structure allowing mark level equalization, which is a complement to the function of extinction ratio enhancement of the classical SA structure, is described. The experimental results at 42.6 Gbit/s show that amplitude fluctuations on both low and high power levels are significantly reduced with the SA tandem regenerator, and the system margin improvements in terms of receiver sensitivity and Q factor are obtained.     

High quality YBCO superconductive thin films fabricated by laser molecular beam epitaxy

High quality YBa₂.Cu₃O_{6 +x}(YBCO) superconductive thin films have been fabricated on the SrTiO₃(100) substrate using laser molecular beam epitaxy (laser-MBE). The active oxygen source was used, which made the necessary ambient oxygen pressure be 2–3 orders lower than that in pulsed laser deposition (PLD). T_c0 is 85–87 K, and J_c, 1.0 × 10⁶ A/cm². Atomic force microscopy (AFM) measurements show that no obvious particulates can be observed and the root mean square roughness is 7.8 nm. High stability DC superconducting quantum interference devices (DC-SQUID) was fabricated using this YBCO thin film.     

LB膜法制备Y2O3掺杂的CeO2超薄陶瓷膜的X光电子能谱(XPS)研究

利用LB膜技术发展了一种制备组分可控的超薄陶瓷膜的方法。以Ce,Y的β－二酮络合物作为表面离子,替代传统的亚相离子,制得混合LB膜。并将它作为前驱物成功制得了Y2O3掺杂的CeO2(YDC)超薄膜。XPS谱表明,膜中Ce与Y的含量比控制得很好。