2 research outputs found
Collective Lasing Behavior of Monolithic GaN–InGaN Core–Shell Nanorod Lattice under Room Temperature
We demonstrated a
monolithic GaN–InGaN core–shell
nanorod lattice lasing under room temperature. The threshold pumping
density was as low as 140 kW/cm<sup>2</sup> with a quality factor
as high as 1940. The narrow mode spacing between lasing peaks suggested
a strong coupling between adjacent whisper gallery modes (WGM), which
was confirmed with the far-field patterns. Excitation area dependent
photoluminescence revealed that the long-wavelength lasing modes dominated
the collective lasing behavior under a large excitation area. The
excitation-area-dependent lasing behavior resulted from the prominent
optical coupling among rods. According to the optical mode simulations
and truncated-rod experiments, we confirmed that the fine-splitting
of lasing peaks originated from the coupled supermodes existing in
the periodic nanorod lattices. With wavelength-tunable active materials
and a wafer-level scalable processing, patterning optically coupled
GaN–InGaN core–shell nanorods is a highly practical
approach for building various on-chip optical components including
emitters and coupled resonator waveguides in visible and ultraviolet
spectral range
Ultracompact Pseudowedge Plasmonic Lasers and Laser Arrays
Concentrating
light at the deep subwavelength scale by utilizing
plasmonic effects has been reported in various optoelectronic devices
with intriguing phenomena and functionality. Plasmonic waveguides
with a planar structure exhibit a two-dimensional degree of freedom
for the surface plasmon; the degree of freedom can be further reduced
by utilizing metallic nanostructures or nanoparticles for surface
plasmon resonance. Reduction leads to different lightwave confinement
capabilities, which can be utilized to construct plasmonic nanolaser
cavities. However, most theoretical and experimental research efforts
have focused on planar surface plasmon polariton (SPP) nanolasers.
In this study, we combined nanometallic structures intersecting with
ZnO nanowires and realized the first laser emission based on pseudowedge
SPP waveguides. Relative to current plasmonic nanolasers, the pseudowedge
plasmonic lasers reported in our study exhibit extremely small mode
volumes, high group indices, high spontaneous emission factors, and
high Purell factors beneficial for the strong interaction between
light and matter. Furthermore, we demonstrated that compact plasmonic
laser arrays can be constructed, which could benefit integrated plasmonic
circuits