Controlling and probing heat generation in an optical heater system

Area of Science:

• Nanophotonics and Plasmonics
• Optical Materials Science
• Thermodynamics at the Nanoscale

Background:

• Understanding light-induced heating in plasmonic nanostructures is crucial for applications requiring precise thermal management.
• Reliable temperature control at the micro/nanometer scale necessitates analysis of local temperature distribution relative to laser power.
• Silver nano-islands (Ag NIs) are investigated for their potential in localized optical heating applications.

Purpose of the Study:

• To design and demonstrate an optical heating system using silver nano-islands (Ag NIs) for micro/nanoscale temperature manipulation.
• To investigate the in situ detection of heat generation and temperature distribution using the fluorescence intensity ratio technique.
• To explore the temperature-dependent upconversion luminescence (UCL) of rare-earth-doped microrods within the controlled heating environment.

Main Methods:

• Fabrication of an optical heating system incorporating silver nano-islands (Ag NIs).
• Exposure of Ag NIs to near-infrared (near-IR) laser light to induce localized heating.
• In situ monitoring of temperature distribution using the fluorescence intensity ratio technique.
• Characterization of temperature-dependent upconversion luminescence (UCL) from Y₂O₃:Yb³⁺/Er³⁺ microrods.

Main Results:

• The optical heating system achieved local temperatures up to 1458 K.
• Temperature control was demonstrated by adjusting the excitation laser power.
• The color of the upconversion luminescence from a single Y₂O₃:Yb³⁺/Er³⁺ microrod was successfully tuned by manipulating the local temperature.
• The color change of the rare-earth microrod served as an indicator for monitoring the local temperature.

Conclusions:

• Real-time manipulation of plasmonic heating is achievable, offering control over thermo-plasmonic effects.
• The developed system enables precise temperature control at the micro/nanoscale.
• The interplay between plasmonic heating and rare-earth luminescence provides a method for both temperature monitoring and optical output tuning.
• This research opens avenues for numerous practical applications leveraging controlled nanoscale thermal effects.