posted on 2021-12-20, 16:37authored byChun Li, Liyun Zhao, Qiuyu Shang, Ruonan Wang, Peng Bai, Jun Zhang, Yunan Gao, Qiang Cao, Zhongming Wei, Qing Zhang
The
development of chip-level near-infrared laser sources using
two-dimensional semiconductors is imperative to maintain the architecture
of van der Waals integrated optical interconnections. However, the
established two-dimensional semiconductor lasers may have either the
disadvantages of poor controllability of monolayered gain media, large
optical losses on silicon, or complicated fabrication of external
optical microcavities. This study demonstrates room-temperature near-infrared
lasing from mechanically exfoliated γ-phase indium selenide
(InSe) microflakes free from external optical microcavities at a center
wavelength of ∼1030 nm. The lasing action occurs at the sub-Mott
density level and is generated by exciton–exciton scattering
with a high net modal optical gain of ∼1029 cm–1. Moreover, the lasing is sustained for microdisks fabricated by
a simple laser printing with a reduced threshold. These results suggest
that InSe is a promising material for near-infrared microlasers and
can be employed in a wide range of applications, including imaging,
sensing, and optical interconnects.