Nonreciprocal Circularly Polarized Lasing from Organic Achiral Microcrystals

Area of Science:

• Photonics
• Organic Electronics
• Materials Science

Background:

• Organic materials offer excellent chiroptical and optical gain properties for circularly polarized (CP) lasers.
• Conventional CP lasers often rely on chiral components, complicating synthesis and fabrication.
• Achieving nonreciprocal behavior in CP lasers is crucial for practical applications.

Purpose of the Study:

• To demonstrate nonreciprocal CP lasing from achiral organic microcrystals.
• To explore the coupling between fluorescence linear anisotropy (f) and linear birefringence (LB) – the f-LB effect.
• To provide a new pathway for designing high-performance nonreciprocal CP lasers.

Main Methods:

• Synthesized triclinic and orthorhombic polymorphs of organic microcrystals via controlled crystallization.
• Investigated the f-LB effect by manipulating molecular packing and crystal structure.
• Analyzed polarization state conversion of photons and amplified the f-LB coupling during lasing oscillation.

Main Results:

• Achiral organic microcrystals exhibited nonreciprocal CP luminescence through the f-LB effect.
• Triclinic crystals showed a stronger f-LB effect due to optimal alignment between the emission plane and birefringence axis.
• Achieved nonreciprocal CP lasing with a high dissymmetry factor of approximately 1.0.

Conclusions:

• The f-LB effect in achiral organic microcrystals enables efficient nonreciprocal CP lasing.
• This approach simplifies device fabrication compared to traditional chiral methods.
• Offers new insights into chiral photonics and paves the way for advanced optoelectronic devices.