  An important building block for on-chip photonic applications is a scaled
emitter. Whispering gallery mode cavities based on III-Vs on Si allow for small
device footprints and lasing with low thresholds. However, multimodal emission
and wavelength stability over a wider range of temperature can be challenging.
Here, we explore the use of Au nanorods on InP whispering gallery mode lasers
on Si for single mode emission. We show that by proper choice of the antenna
size and positioning, we can suppress the side-modes of a cavity and achieve
single mode emission over a wide excitation range. We establish emission trends
by varying the size of the antenna and show that the far-field radiation
pattern differs significantly for devices with and without antenna.
Furthermore, the antenna-induced single mode emission is dominant from room
temperature (300 K) down to 200 K, whereas the cavity without an antenna is
multimodal and its dominant emission wavelength is highly temperature
dependent.
