High-quality GaNAs/GaAs quantum wells with light emission up to 1.44 mu m grown by molecular-beam epitaxy

High-quality GaNAs/GaAs quantum wells with high substitutional N concentrations, grown by molecular-beam epitaxy, are demonstrated using a reduced growth rate in a range of 0.125-1 mu m/h. No phase separation is observed and the GaNAs well thickness is limited by the critical thickness. Strong room-temperature photoluminescence with a record long wavelength of 1.44 mu m is obtained from an 18-nm-thick GaN0.06As0.94/GaAs quantum well. (C) 2005 American Institute of Physics.

4×4热光SOI波导开关阵列

设计并制作了阻塞型和完全无阻塞型4×4热光SOI(silicon-on-insulator)波导开关阵列.开关单元采用了多模干涉耦合器(MMI)-MZI(Mach-Zehnder intederometer)结构的2×2光开关.阻塞型光开关附加损耗为4.8～5.4 dB,串扰为-21.8 dB～-14.5 dB.完全无阻塞型光开关阵列附加损耗为6.6～9.6 dB,串扰为-25.8～-16.8 dB.两者的消光比都在17～25 dB内变化,开关单元功耗小于230 mW.器件的开关时间小于3μs.功耗和开关速度都明显优于SiO_2基和聚合物基的开关阵列.

Design and Fabrication of Thermo-Optic 4×4 Switching Matrix in Silicon-on-Insulator

A rearrangeable nonblocking thermo-optic 4×4 switching matrix,which consists of five 2×2 multimode interference-based Mach-Zehnder interferometer(MMI-MZI) switch elements，is designed and fabricated.The minimum and maximum excess loss for the matrix are 6.6 and 10.4dB,respectively.The crosstalk in the matrix is measured to be between －12 and －19.8dB.The switching speed of the matrix is less than 30μs.The power consumption for the single switch element is about 330mW.