Time resolved emission at 1.3 μm of a single InAs quantum dot by using a tunable fibre Bragg grating

Area of Science:

• Materials Science
• Quantum Optics
• Nanotechnology

Background:

• Metamorphic InAs/GaAs quantum dots (QDs) are crucial for optoelectronic devices emitting at 1.3 μm.
• Efficient characterization of single QDs is essential for understanding their properties.
• Conventional characterization methods often suffer from low light collection efficiency.

Purpose of the Study:

• To develop and demonstrate a novel fiber-based characterization setup for single metamorphic InAs/GaAs quantum dots (QDs).
• To enhance the light collection efficiency for photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurements.
• To identify and analyze exciton transitions and recombination dynamics in these QDs.

Main Methods:

• Utilized a novel fiber-based setup for photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurements.
• Employed a wavelength-tunable fiber Bragg grating (FBG) filter to enhance light collection efficiency.
• Applied a random population model to analyze spectral data from single InAs/GaAs QDs.

Main Results:

• Achieved a light collection efficiency increase of over one order of magnitude compared to conventional grating monochromators.
• Identified single charged exciton and neutral biexciton transitions in the InAs/GaAs QDs.
• Demonstrated that QD recombination dynamics under pulsed excitation align with weak quantum confinement and carrier interactions.

Conclusions:

• The novel fiber-based setup offers a significant improvement in characterizing single metamorphic InAs/GaAs QDs.
• The identified exciton transitions and recombination dynamics provide insights into carrier behavior within the QDs.
• This advanced characterization technique facilitates the development of next-generation optoelectronic devices.