Circularly Polarized Laser Emission from an Electrically Pumped Chiral Microcavity

Engineering the chirality of optical microcavities is a central concept of modern photonics to gain full control the polarization of the confined electromagnetic mode. Here, we demonstrate a compact source of coherent radiation based on an electrically driven, chiral semiconductor microcavity. The device is composed of an AlAs/(Al, Ga)As microcavity containing multiple GaAs quantum wells in the active region and a chiral photonic crystal slab etched in the upper distributed Bragg reflector. The structure promotes laser oscillation under electrical current injection in the near-infrared spectral range (h omega similar or equal to 1.565 eV) and degrees of circular polarization exceeding 90%. The sense of circular polarization is controlled by the handedness of the chiral photonic crystal slab and changes to the opposite one in a mirror-symmetrical structure. Our results represent an important step towards the practical implementation of compact sources of circularly polarized light.

Automated summary

Engineering the chirality of optical microcavities is a central concept in modern photonics. We demonstrate a compact source of coherent radiation based on an electrically driven, chiral semiconductor microcavity. The device can produce circularly polarized light with polarization exceeding 90% and the direction of polarization can be controlled by the handedness of the chiral photonic crystal slab.