3 research outputs found
Design and Control of Mode Interaction in Coupled ZnTe Optical Microcavities
The
photonics involving II–VI epitaxial layers was limited
so far to structures based on a single planar microcavity. Here, we
present double vertically coupled ZnTe optical microcavities in planar
and 3-D photonic molecule geometry. We design the structures with
the help of transfer matrix method calculations and we establish their
fabrication technology using molecular beam epitaxy. We characterize
the samples by reflectivity spatial mapping and study them by angle-integrated
and angle-resolved photoluminescence and reflectivity. We efficiently
tailor the interaction strength of the optical cavities modes by adjusting
the spatial separation between the microcavities, their thickness
ratio, and the size of the micropillars etched out of the planar structure.
Coupling constants extracted from our measurements agree with those
determined in calculations in the frame of a tight-binding approach
applied to one-dimensional photonic structures
Magneto-optical induced supermode switching in quantum fluids of light
The insensitivity of photons towards external magnetic fields forms one of the hardest barriers against efficient magneto-optical control, aiming at modulating the polarization state of light. However, there is even scarcer evidence of magneto-optical effects that can spatially modulate light. Here, we demonstrate the latter by exploiting strongly coupled states of semimagnetic matter and light in planar semiconductor microcavities. We nonresonantly excite two spatially adjacent exciton-polariton condensates which, through inherent ballistic near field coupling mechanism, spontaneously synchronise into a dissipative quantum fluidic supermode of definite parity. Applying a magnetic field along the optical axis, we continuously adjust the light-matter composition of the condensate exciton-polaritons, inducing a supermode switch into a higher order mode of opposite parity. Our findings set the ground towards magnetic spatial modulation of nonlinear light
Inhibition and Enhancement of the Spontaneous Emission of Quantum Dots in Micropillar Cavities with Radial-Distributed Bragg Reflectors
We present a micropillar cavity where nondesired radial emission is inhibited. The photonic confinement in such a structure is improved by implementation of an additional concentric radial-distributed Bragg reflector. Such a reflector increases the reflectivity in all directions perpendicular to the micropillar axis from a typical value of 15–31% to above 98%. An inhibition of the spontaneous emission of off-resonant excitonic states of quantum dots embedded in the microcavity is revealed by time-resolved experiments. It proves a decreased density of photonic states related to unwanted radial leakage of photons out of the micropillar. For on-resonance conditions, we find that the dot emission rate is increased, evidencing the Purcell enhancement of spontaneous emission. The proposed design can increase the efficiency of single-photon sources and bring to micropillar cavities the functionalities based on lengthened decay times