“We've successfully demonstrated sub-wavelength nanowire device operation on a silicon platform," said scientist Masaya Notomi at NTT Basic Research Laboratories.
According to the team, previous attempts to place a variety of functional nanowires within photonic circuits have shown nanowires to be too small to confine light. While bigger nanowires can improve the light confinement and performance, it increases both energy consumption and device footprint.
"We prepared a III-V semiconductor nanowire with sufficiently large optical gain and placed it within a slot of a silicon photonic crystal, which results in an optical nanoresonator," said researcher Masato Takiguchi.
"We've demonstrated that this sub-wavelength nanowire can exhibit continuous-wave lasing oscillation and high speed signal modulation at 10Gbit/s."
“The lasing wavelength should be longer than 1.2microns to avoid absorption in silicon,” Takiguchi explained. “So it's important to create sub-wavelength nanowire lasers at optical communication wavelengths – 1.3 to 1.55microns – capable of high speed signal modulation.".
"Our result is the first demonstration of continuous-wave lasing oscillation by a sub-wavelength nanowire, as well as the first demonstration of high speed signal modulation by a nanowire laser," Notomi claimed.
The group achieved 10Gbit/s modulation, which is said to be comparable to conventional, directly modulated high speed lasers used for optical communications.
Applications include nanowire-based photonic integration circuits to create lasers, photodetectors, and switches.