Tunable multi-wavelength optofluidic Dammann grating with beam splitting property.

Area of Science:

• Optics and Photonics
• Microfluidics
• Materials Science

Background:

• Traditional Dammann gratings (DGs) are solid-state devices with fixed optical properties.
• The inability to modulate their working wavelength limits their application in dynamic optical systems.

Purpose of the Study:

• To engineer a Dammann grating (DG) with tunable and multi-wavelength beam-splitting capabilities.
• To overcome the limitations of fixed-wavelength solid DGs through a novel liquid-solid hybrid design.

Main Methods:

• Fabrication of a liquid-solid hybrid structure using photoresist gratings and drilled glass plates.
• Integration with a microfluidic mixer to control the refractive index of the internal liquid medium.
• Real-time tunability achieved by adjusting the flow rates of miscible liquids.

Main Results:

• Demonstrated well-controlled beam splitting with uniform spot arrangement (7x7 array) at different wavelengths (632.8 nm and 532 nm).
• Achieved high spot size and power uniformity (e.g., ~78% and ~71% at 632.8 nm).
• Confirmed suitability for near-infrared light, highlighting broad spectral applicability.

Conclusions:

• The liquid-solid hybrid tunable Dammann grating (DG) offers simple fabrication and wavelength tunability.
• This novel DG design presents significant advantages over traditional solid gratings for optofluidic networks and optical devices.
• Represents a breakthrough in adaptable beam-splitting technology for versatile optical applications.