Photonic architectures provide a powerful strategy to enhance the performance of optoelectronic devices, particularly those requiring efficient manipulation of light polarization. Circularly polarized light is of growing importance for applications including optical communications, quantum technologies, imaging, and advanced display systems. However, most materials exhibit inherently weak chiroptical responses, while existing chiral nanophotonic platforms often rely on complex, expensive nanofabrication techniques that hinder large-scale implementation. Therefore, the development of scalable, cost-effective fabrication methods is essential to bring these technologies into practical optoelectronic devices.

In Prof. Mihi’s research group, we employ soft nanoimprint lithography, a versatile, rapid, and low-cost technique capable of fabricating sub-100 nm photonic nanostructures over areas as large as 1 cm². By imprinting chiral nanostructures, we create scalable photonic platforms capable of transferring chirality to otherwise achiral emitters, enabling the direct generation of circularly polarized light without the need for additional optical components that reduce efficiency and hinder on-chip integration.

In a first work^[1], this methodology enables the fabrication of chiral nanophotonic structures that efficiently transfer chirality to otherwise achiral emitters, eliminating the need for external polarization optics that introduce optical losses and complicate on-chip integration. We demonstrate this concept using a broad range of emitters across the visible spectrum, including CdSe/CdS quantum dots and nanoplatelets, CsPbBr₃ and CsPbI₃ perovskite nanocrystals, F8BT, and organic dyes. This architecture can produce strong circular dichroism and highly circularly polarized photoluminescence with dissymmetry factors exceeding g_lum > > 1.

Beyond spontaneous emission, we extend the strategy to coherent light sources by exploiting chiral bound states in the continuum (BICs) ^[2]. Although BIC-based chiral lasers typically rely on complex and expensive nanofabrication techniques, our soft nanoimprint approach enables their scalable production. By embedding an organic dye within the chiral patterned resist, coupling between the emitter and chiral bound states in the continuum (BICs) produces nearly fully circularly polarized laser emission, reaching polarization degrees of approximately 97%.

Overall, our work demonstrates that soft nanoimprint lithography is a powerful manufacturing platform for scalable nanophotonics, enabling broadband chiral emission, highly efficient circularly polarized light generation, and chiral lasing in architectures compatible with large-area production. These advances pave the way toward practical photonic technologies for future optoelectronic applications.