Optofluidic tunable broadband distributed Bragg reflector based on liquid crystal polymer composites

Area of Science:

• Photonics
• Materials Science
• Microfluidics

Background:

• Dynamically reconfigurable photonic devices are crucial in modern liquid crystal (LC) photonics.
• Distributed Bragg reflectors (DBRs) are key optical components, but their tunability is often limited.

Purpose of the Study:

• To present a continuously tunable DBR based on LC polymer composites.
• To demonstrate a novel optofluidic method for modulating LC-templated DBR films.
• To explore the application of these devices in microfluidic analysis.

Main Methods:

• Fabrication of LC-templated DBR films via photopolymerization under visible standing wave interference.
• Investigating the effects of incident angle, light intensity, and ethanol concentration on reflection.
• Integration of DBR films into microfluidic channels for reversible solvent refilling.

Main Results:

• Demonstrated dynamic and continuous variation of the reflection band by altering the refractive index of mixed liquids and adjusting flow rates.
• Observed tunability within a specific visible light band.
• Characterized the influence of various parameters on DBR reflection behavior.

Conclusions:

• The developed optofluidic DBRs offer a novel approach to dynamic photonic device reconfiguration.
• This technology provides an alternative to conventional regulation methods (electric, optical, temperature fields).
• Potential applications in microfluidic analysis techniques utilizing structural color are anticipated.