Nanobeam photonic crystal cavity quantum dot laser

Area of Science:

• Semiconductor Nanophotonics
• Quantum Dot Lasers
• Nanocavity Engineering

Background:

• One-dimensional nanobeam cavities are crucial for integrated photonic circuits.
• Indium arsenide (InAs) quantum dots offer tunable emission for laser applications.
• Room-temperature operation is essential for practical optoelectronic devices.

Purpose of the Study:

• To investigate the lasing behavior of GaAs nanobeam cavities with embedded InAs quantum dots at room temperature.
• To determine the pump wavelength dependence of the lasing threshold.
• To demonstrate wavelength tuning of the nanobeam cavity lasers.

Main Methods:

• Fabrication of one-dimensional GaAs nanobeam cavities containing InAs quantum dots.
• Optical characterization of lasing properties under 780 nm and 980 nm optical pumping.
• Wavelength tuning using a near-field fiber taper for pumping and emission collection.

Main Results:

• Room-temperature lasing was observed across the quantum dot photoluminescence spectrum.
• Threshold pump powers as low as 0.3 microW (780 nm) and 19 microW (980 nm) were achieved.
• Wavelength tuning of up to 7 nm was demonstrated using the fiber taper.

Conclusions:

• GaAs nanobeam cavities with InAs quantum dots exhibit efficient room-temperature lasing.
• The fiber taper enables both efficient pumping and active wavelength control of the cavity lasers.
• This work highlights the potential for tunable, low-threshold quantum dot lasers in nanophotonic systems.