nn9b04925_si_001.pdf (854.95 kB)
Surface-Emitting Perovskite Random Lasers for Speckle-Free Imaging
journal contribution
posted on 2019-08-23, 16:37 authored by Yilin Liu, Wenhong Yang, Shumin Xiao, Nan Zhang, Yubin Fan, Geyang Qu, Qinghai SongRandom
lasers have been ideal illumination sources for speckle-free
and high-speed imaging. Despite their successes, the real applications
of random lasers are facing a long-standing challenge, i.e., the cumbersome size of the illuminating system. Herein, we demonstrate
perovskite-based surface emitting random lasers (SERLs) and explore
their applications in speckle-free imaging. The random lasers are
generated by multiple scattering in a perovskite polycrystalline film
sandwiched by two distributed Bragg reflectors. Owing to the tight
confinement in vertical direction and large number of random resonances,
the wavevectors of random lasers are dominated by their vertical components,
and thus, multimode SERLs with a divergence angle of ∼3–5°
and low spatial coherence are produced. By directly illuminating the
patterns with the SERLs, the notable speckle noises of conventional
optical images have been dramatically suppressed. This research shall
provide a strategy toward the integrated spectral-free imaging systems.