Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low threshold, room-temperature microdisk lasers in the blue spectral
  range   InGaN-based active layers within microcavity resonators offer the potential
of low threshold lasers in the blue spectral range. Here we demonstrate
optically pumped, room temperature lasing in high quality factor GaN microdisk
cavities containing InGaN quantum dots (QDs) with thresholds as low as 0.28
mJ/cm2. This work, the first demonstration of lasing action from GaN microdisk
cavities with QDs in the active layer, provides a critical step for the
nitrides in realizing low threshold photonic devices with efficient coupling
between QDs and an optical cavity.

2
The categories of this paper are: math
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph