Liquid-crystal random fiber laser for speckle-free imaging

Abstract

Liquid crystal random fiber lasers (LC-RFLs) exhibit low spatial coherence, extraordinary tunability, and high flexibility and are therefore promising for use in imaging and related applications. They nevertheless suffer from ineffective emission along the fiber axis. This work develops an end-emitting LC-RFL that is based on a pump-induced gain–loss structure, which effectively modulates the optical feedback, thereby providing directional random lasing along the fiber. The laser emission comprises ∼10 000 transverse spatial modes that are mutually incoherent, resulting in a negligible speckle contrast of ∼0.7% (far below the speckle-perception threshold of human eyes). The developed LC-RFL is used to perform speckle-free full-field imaging in a setting with strong optical crosstalk in a multimode fiber. Our findings support the potential widespread use of LC-RFL as a spatially incoherent, flexible laser source.

Plasmonic random laser enabled artefact-free wide-field fluorescence bioimaging: uncovering finer cellular features

“…Owing to their low spatial coherence, random lasers effectively reduce the speckle contrast instantaneously, and provide a good signal to noise ratio even in highly scattering environments. 37–39…”

Photothermal Effect Controlled Complex Lasing for Decentralized Key Distribution

“…Light–light or light–matter interaction in complex media has been a promising topic, which provides new perspectives for the development of light control and applications in imaging, sensing, secret communication, and optical network, − wherein chaotic, disordered, or random lasing in deformed cavities, irregular structures, or media has become increasingly attractive for multidiscipline applications. − …”

Substrate Effects on the Random Lasing Performance of Solution-Processed Hybrid-Perovskite Multicrystal Film

“…Multicrystalline structures with randomly distributed interfaces have supplied the optical scattering centers in most of the cases. Although random lasers are categorized into coherent [11][12][13][14] and incoherent types [15][16][17], reported random lasing processes using HOIPs are mostly based on incoherent processes, so that broad-band emission spectra are observed for these lasers.…”