ANR LUTEM

Project Coordinator: Sophie Meuret (CEMES), Toulouse

Partners:

L2C, Montpellier
CRHEA, Sophia Antipolis
CEMES, Toulouse

Duration: 2024–2028

Semiconductor nanowire lasers are promising nanoscale components for technological breakthroughs in quantum computation, communication, and bio-sensing. They are cheap, require low energy, and can be tailored to specific applications by tuning the wire dimensions and material. Their lasing properties are highly sensitive to nanoscale irregularities in the gain material.

However, due to a lack of suitable tools, these properties have only been studied in the far field, and modeling approaches ignore nanoscale features by assuming a homogeneous material gain and perfect cylindrical cavity.

In the LUTEM project, by combining our expertise in nanowire design (CRHEA), optical characterization (L2C), and ultrafast electron microscopy (CEMES), we will zoom in for the first time on the nanoworld of operational nanowire lasers, achieving a sub-wavelength understanding of a single nanowire while it is lasing.

To this end, we will develop two unique experiments inside an ultrafast transmission electron microscope and apply them to the study GaN-based nanolasers :

The first experiment will allow us to make a subwavelength mapping of cavity mode resonances, strengths, and dynamics at and above the lasing threshold to describe nanolaser systems in operation, taking their non-ideal shape, end-facet reflectivity, and surface irregularities into consideration.
The second experiment will map the material gain coefficient below and above the lasing threshold, and relate the outcomes to crystallographic defects and doping heterogeneities.

These new insights will pave the way for a novel approach to model and design nanolasers. It is an essential step in the investigation of increasingly complex nanolaser-based systems such as nanolasers coupled to plasmonic waveguides for photonic circuit integration, or quantum dot-based lasers.