Gradient-index optofluidic waveguide in polydimethylsiloxane.

Area of Science:

• Optofluidics
• Materials Science
• Optical Engineering

Background:

• Optofluidic devices integrate optical functionalities with microfluidic systems.
• Gradient-index (GRIN) materials offer unique light-guiding properties.
• Evanescent sensing requires efficient light confinement near a medium interface.

Purpose of the Study:

• To demonstrate a novel gradient-index (GRIN) optofluidic waveguide.
• To enable efficient light localization for evanescent sensing applications.
• To characterize the optical performance of the fabricated waveguide.

Main Methods:

• Fabrication of a polydimethylsiloxane waveguide using radially varied temperature curing.
• Integration of the waveguide with a microfluidic channel.
• Optical characterization, including propagation loss measurement at 632.8 nm.

Main Results:

• Successful fabrication of a GRIN optofluidic waveguide.
• Demonstrated effective light confinement around the microfluidic channel.
• Achieved a low propagation loss of 1.47 dB/cm at 632.8 nm.

Conclusions:

• The GRIN optofluidic waveguide is suitable for evanescent sensing.
• The fabrication method allows for precise control over optical properties.
• The device exhibits promising performance for integrated optical sensing.