Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phase-change perovskite tunable microlaser   Since the invention of the laser, adoption of new gain media and device
architectures has provided solutions to a variety of applications requiring
specific power, size, spectral, spatial, and temporal tunability. Here we
introduce a fundamentally new type of tunable semiconductor laser based on a
phase-change perovskite metasurface that acts simultaneously as gain medium and
optical cavity. As a proof of principle demonstration, we fabricate a
subwavelength-thin perovskite metasurface supporting bound states in the
continuum (BICs). Upon the perovskite structural phase transitions, both its
refractive index and gain vary substantially, inducing fast (1.35 nm/K rate)
and broad spectral tunability (>15 nm in the near-infrared), deterministic
spatial mode hopping between polarization vortexes, and hysteretic optical
bistability of the microlaser. These features highlight the uniqueness of
phase-change perovskite tunable lasers, which may find wide applications in
compact and low-cost optical multiplexers, sensors, memories, and LIDARs.

25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin