Lasing in liquid crystal systems with a deformed lying helix

Area of Science:

• Materials Science
• Optics and Photonics
• Condensed Matter Physics

Background:

• Chiral liquid crystals (CLCs) exhibit unique optical properties due to their helical structure.
• The deformed lying helix (DLH) state in CLCs presents a unique configuration with potential for photonic applications.
• Understanding field-induced transitions in CLCs is crucial for developing advanced optical devices.

Purpose of the Study:

• To experimentally investigate the lasing effect in novel chiral liquid crystal systems.
• To study lasing in both odd- and even-order field-induced stop-bands characteristic of the DLH state.
• To explore the low-threshold lasing phenomenon in DLH CLC systems with fine spectral structures.

Main Methods:

• Fabrication of special CLC cells with periodic boundary conditions and flipped surface alignment (planar and vertical).
• Preparation of alignment surfaces using focused ion-beam lithography.
• Application of electric fields to induce orientational transitions from Grandjean-plane texture to the DLH state.
• Spectroscopic analysis to observe and study lasing on fine-structured photonic stop-bands.

Main Results:

• Successful achievement of the DLH state in CLC systems via controlled surface alignment and electric fields.
• Observation of field-induced photonic stop-bands with fine spectral structures in the DLH state.
• Demonstration of low-threshold lasing effect on these fine-structured sub-bands.
• Lasing was studied for both odd- and even-order stop-bands, exclusive to the DLH state.

Conclusions:

• Novel chiral liquid crystal systems in the DLH state exhibit promising low-threshold lasing properties.
• The DLH state, induced by electric fields and specific boundary conditions, supports unique photonic stop-bands suitable for lasing.
• This research opens avenues for developing new laser sources based on engineered liquid crystal photonic structures.