Microscale Temperature Shaping Using Spatial Light Modulation on Gold Nanoparticles

Area of Science:

• Microscale thermal engineering
• Nanophotonics
• Biomedical engineering

Background:

• Focused lasers enable microscale heating for applications in biomedicine, biology, and microfluidics.
• Gold nanoparticles efficiently absorb light for laser-based heating.
• Conventional laser heating produces non-uniform, Gaussian-like temperature profiles due to heat diffusion.

Purpose of the Study:

• To experimentally generate arbitrary temperature distributions (uniform, linear, parabolic) on the micrometric scale.
• To overcome the limitations of non-uniform heating inherent in traditional laser-based microscale thermal applications.

Main Methods:

• Illuminating a uniform gold nanoparticle distribution on a planar substrate with spatially contrasted laser beams.
• Shaping laser beams using a spatial light modulator (SLM) to control light patterns.
• Calculating the required light pattern and SLM interferogram for desired temperature profiles.
• Employing quantitative wavefront sensing for temperature measurements.

Main Results:

• Demonstrated the ability to create non-Gaussian, arbitrary temperature profiles at the microscale.
• Successfully computed and implemented light patterns using an SLM to achieve specific temperature distributions.
• Validated the generated temperature profiles through precise measurements using quantitative wavefront sensing.

Conclusions:

• The developed method enables precise control over microscale temperature profiles.
• This technique offers a versatile tool for applications requiring tailored thermal management at the microscale.
• The findings pave the way for advanced applications in fields utilizing microscale heating with gold nanoparticles.