Circularly Polarized Laser with Chiral Nematic Cellulose Nanocrystal Cavity

Circularly polarized (CP) lasers derived from low- cost and renewable raw sources are attracting increasing attention in photonics and material science. Here, we present a facile and effective approach to fabricate CP lasers by the evaporation- induced assembly of cellulose nanocrystals (CNCs) and a laser dye. The obtained laser exhibits a controlled chiral nematic structure, which acts as a chiral optical cavity, and varied chiral coupling interactions. It is shown that the CNC-based laser can modify the polarization state of the laser into left-handed polarization, leading to strong CP laser emission (CPLE) with a dissymmetry factor up to 0.35. The chiral nematic CNC structure proves to be a versatile yet straightforward strategy to generate strong and tailored CPLE.

Automated summary

A method of fabricating circularly polarized lasers using cellulose nanocrystals and a laser dye through evaporation-induced assembly is presented, showing controlled chiral nematic structure and modification of laser polarization state into left-handed, resulting in strong and tailored CP laser emission.