Temporal, thermal, and light stability of continuously tunable cholesteric liquid crystal laser array

Area of Science:

• Photonics and Liquid Crystal Technology
• Advanced Laser Materials

Background:

• Cholesteric liquid crystals (CLCs) are known for their unique optical properties.
• Developing stable, tunable laser devices is crucial for various photonic applications.

Purpose of the Study:

• To realize fine-structured polymerized cholesteric liquid crystal (PCLC) wedge laser devices.
• To investigate the stability of PCLC wedge lasers under temporal, light, and thermal perturbations.
• To assess the practical viability of PCLC lasers for device development.

Main Methods:

• Fabrication of fine-structured PCLC wedge laser devices.
• Characterization of lasing wavelength tunability and spectral resolution.
• Evaluation of device stability under prolonged time, strong external light, and thermal stress.

Main Results:

• Achieved high spatial tunability of lasing wavelength with resolution < 0.3 nm.
• Obtained over 100 laser lines from a single PCLC cell without additional components.
• Demonstrated good temporal stability over 1 year and robustness to perturbations (wavelength shift < 1 nm).
• Observed a decrease in laser peak intensities (up to 34%) and a 3 nm red shift in PBG edge due to temperature.

Conclusions:

• The polymerization of CLC via UV curing imparts significant stability to the PCLC wedge laser devices.
• Despite minor intensity decreases and wavelength shifts, the remaining performance is considerable for practical use.
• These findings support the development of practical CLC laser devices.