A new mechanism for polarization rotation in rib waveguides is suggested and demonstrated in InP waveguides. The polarization rotation is achieved by loading a rib waveguide in a periodic asymmetric way. Complete TE↔TM conversion, with only 2–3 dB excess loss, is obtained in a 3.7-mm-long InP loaded waveguide. Strong polarization rotation (80%), in shorter devices (0.3 mm long), is also demonstrated.
Spatially localized femtosecond pulses have been produced by a combination of scanning near-field optical microscopy with ultrashort pulse lasers. With these pulses direct ablative writing on metal surfaces is demonstrated. Possible applications of this technique for nanostructuring, repair, and production of lithographic masks are discussed.
A Si3N4 core waveguide, matched to a laser mode, is adiabatically tapered into a SiO2:P core waveguide, matched to a fiber mode. When used to couple the light from a semiconductor laser into an optical fiber, a loss of 3.1 dB is obtained, compared to a loss of 4.5 dB obtained with a lensed fiber.
An adiabatic polarization splitter, fabricated with silica and silicon nitride films on a silicon substrate, is demonstrated. A rejection of the unwanted polarization (cross talk) of −20 to −34 dB was achieved with single filtering and −35 to −45 dB with double filtering. The device had a 1.5 dB insertion loss and a very small wavelength dependence.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.