Super-resolved snapshot hyperspectral imaging of solid-state quantum emitters for high-throughput integrated quantum technologies

Abstract

Solid-state quantum emitters coupled to integrated photonic nanostructures are quintessential for exploring fundamental phenomena in cavity quantum electrodynamics and are used in a wide range of photonic quantum technologies. One of the most exciting prospects for integrated photonics is the potential for massive production of miniaturized devices on a single chip. However, the efficiency and reproducibility of light–matter coupling are hindered by the spectral and spatial mismatch between the single solid-state quantum emitters and the optical modes supported by the photonic nanostructures. Here we develop a platform and method for hyperspectral imaging of solid-state quantum emitters to address this long-standing issue. Spatially distributed and spectrally broadened InAs quantum dots are embedded in a GaAs/AlGaAs one-dimensional (1D) planar cavity that consists of two distributed Bragg reflectors acting as mirrors. By exploiting the extended mode of the dispersive 1D cavity and the way it shapes the out-of-plane emission from the quantum dots, we extract the spatial position and emission wavelength of each dot from a single wide-field photoluminescence image, with a spatial and spectral accuracy down to 15 nm and 0.4 nm, respectively. We then fabricate quantum light sources by etching the 1D confined planar cavity into 3D confined micropillars. Extension of this technique using an open planar cavity can be exploited for a variety of compact quantum photonic devices with expanded functionalities for large-scale integration. Our technology is particularly appealing for quantum photonic applications that involve the spatial and spectral characterization of a large number of solid-state quantum emitters. The position and emission wavelengths of single quantum dots embedded in a one-dimensional planar cavity can be simultaneously determined from a single photoluminescence image with 15 nm spatial accuracy and subnanometric spectral accuracy in the near-infrared.