Multimode Robust Lasing in a Dye-Doped Polymer Layer Embedded in a Wedge-Shaped Cholesteric.

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Cholesteric liquid crystals (CLCs) are key for tunable coherent light sources.
• Induced defects in CLCs offer unique optical properties.
• Controlling defect modes' spectral properties is crucial for device applications.

Purpose of the Study:

• Investigate laser generation possibilities in dye-doped polymer layers within wedge-shaped CLCs.
• Analyze the spectral control and behavior of induced defect modes.
• Explore the potential for compact, low-threshold, and tunable coherent light sources.

Main Methods:

• Utilized a dye-doped polymer layer embedded in a wedge-shaped CLC.
• Employed simulations based on the Berreman 4x4 matrix approach.
• Investigated a wide range of CLC thicknesses.

Main Results:

• Demonstrated multimode laser generation due to multiple defect modes within the photonic bandgap (PBG).
• Observed both periodic and continuous generation of defect modes along specific spectral lines.
• Identified a unique and robust spectral behavior of induced defect modes.

Conclusions:

• Multimode laser generation is achievable in CLCs with induced defects.
• The observed spectral behavior of defect modes is unique and promising for advanced photonic devices.
• This research expands the application range of CLC-based coherent light sources.