Multimotion of Marangoni Propulsion Ships Controlled by Two-Wavelength Near-Infrared Light.

Multimode motion of Marangoni propulsion ships on a water surface as per a near-infrared, two-wavelength selective response is achieved for the first time. The ships are rhombus- or propeller-shaped polyacrylamide or siloxane resin-based gels in which NdO and YbO nanoparticles are incorporated separately for photothermal conversion at 808 and 980 nm, respectively. The rhombus geometry is for straight locomotion, and the propeller geometry is for rotation.

Highly time-resolved correlation measurement between laser and synchrotron radiation pulses without synchronization control.

A mode-locked laser has been introduced in combination with synchrotron radiation to establish a versatile technique for highly time-resolved correlation measurements utilizing the short-pulse and high-pulse frequency characteristics of both photon sources. Successive pulse timing delay detected by nonlinear optical mixing between the two sources yields a cross-correlation profile capable of accurate measurement of the picosecond pulse profile of the synchrotron radiation without any synchronization control. Although the experiment was performed in the visible spectral domain, the present technique opens up a methodology for time-resolved spectroscopy in femtosecond and higher-energy domains by introducing a suitable nonlinear process that informs of the pulse coincidence between the two radiation sources.