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Router-to-router all-optical wavelength path rerouting using generalized multiprotocol label switching protocol has been successfully carried out including photonic cross-connect and dense wavelength-division-multiplexing equipment. The rerouting time was measured to be shorter than 7 s. [ABSTRACT FROM PUBLISHER]

We demonstrate a low-threshold distributed reflector laser, consisting of a distributed feedback section with wirelike active regions and a passive distributed Bragg reflector section with narrower ones, by utilizing the lateral quantum confinement effect. A threshold current under the room-temperature continuous-wave condition as low as 3.2 mA, which corresponds to a threshold current density of 290 A/cm2, was obtained with the stripe width of 4.3 μm and the active region length of 260 μm. The differential quantum efficiency of 19% from the front facet, a high output ratio of 11 from the front facet to the rear facet, and a submode suppression ratio of 47 dB at a bias current 3.75 times the threshold were also achieved. [ABSTRACT FROM PUBLISHER]

We report on the low-threshold operation of membrane buried heterostructure distributed feedback laser arrays. 45 devices were fabricated on a wafer covering a wide wavelength range of 75 nm. The lowest threshold pump power as low as 0.64 mW along with the submode suppression-ratio of over 30 dB at two times the threshold were successfully obtained at room-temperature continuous-wave condition. [ABSTRACT FROM PUBLISHER]

Narrow-stripe 1.55-μm wavelength distributed reflector lasers consisting of both distributed Bragg reflectors and vertical grating of the first Bragg order were fabricated. A low threshold current Ith of 2.8 mA, a differential quantum efficiency ηd of 28% from the front facet, and a submode suppression ratio of 44 dB were obtained for structures with a stripe width of 1.3 μm and a cavity length of 150 μm. [ABSTRACT FROM PUBLISHER]

This study investigates a liquid-piston Stirling engine in which the solid pistons of conventional Stirling engines are replaced by U-shaped liquid columns. The engine has a loop structure made of a chain of unit sections. consisting of liquid columns and gas columns. Simultaneous measurements of pressure and velocity oscillations in the gas column provide experimental evidence of the execution of the Stirling thermodynamic cycle with relatively small viscous losses in the regenerator. An analysis based on thermoacoustic theory clarifies how many unit sections should be used to build the engine. The results show that engines composed of three to five unit sections ensure stable low-temperature-ratio operation. [ABSTRACT FROM AUTHOR]