Fiber-integrated microcavities for efficient generation of coherent acoustic phonons

Abstract

Coherent phonon generation by optical pump-probe experiments has enabled the study of acoustic properties at the nanoscale in planar heterostructures, plasmonic resonators, micropillars and nanowires. Focalizing both pump and probe on the same spot of the sample is a critical part of pumpprobe experiments. This is particularly relevant in the case of small objects. The main practical challenges for the actual implementation of this technique are: stability of the spatio-temporal overlap, reproducibility of the focalization and optical mode matching conditions. In this work, we solve these three challenges for the case of planar and micropillar optophononic cavities. We integrate the studied samples to single mode fibers lifting the need for focusing optics to excite and detect coherent acoustic phonons. The resulting excellent reflectivity contrast of at least 66% achieved in our samples allows us to observe stable coherent phonon signals over at least a full day and signals at extremely low excitation powers of 1µW. The monolithic sample structure is transportable and could provide a means to perform reproducible plug-and-play experiments.

Simultaneous confinement of acoustic phonons and near infrared photons in GaAs/AlAs multilayers by band inversion

“…10 Finally, the concept of colocalization can be extended to 3D micropillars. [53][54][55][56][57] Since GaAs/AlAs heterostructures are widely used in optoelectronics and photonics, 58,59 the engineering of acoustic phonons becomes directly accessible in existing structures.…”

Fiber-coupled quantum light sources based on solid-state quantum emitters

“…a QD) into a nanophotonic structure [62]. Fibers can be directly glued to pre-fabricated on-chip structures like a micromesa [128] by employing optical interferometry right through the fiber to determine the center of the structure [127] shown in figure 9 or by monitoring the local emission [84,129] or the dip [130,131] of a microcavity as or its transmitted light [85] in active optical-feedback alignment approaches (see figure 10).…”

“…However, the controlled fiber coupling of individual photonic structures is the goal, and has already been reported for micromesas [127], nanowires [160], and micropillars [130,131]. We refrain from a detailed analysis here and refer to the already mentioned tables at the end of the article, as we would like to highlight three publications that show the state-of-the-art [85,150,161].…”

Plug‐and‐Play Single‐Photon Devices with Efficient Fiber‐Quantum Dot Interface

“…Intermediate optical systems [27,28] or microstructured optical fibers [29] can improve fiber coupling efficiency; however, continuous adjustment of the optical alignment is unavoidable to maintain this efficiency. Integrating QDs into 3D micro/nanophotonic structures, such as micropillars, [30,31] nanowires, [32] and monolithic lenses [33][34][35] can significantly enhance light extraction and produce Gaussian-like far-field patterns. However, these methods are based on chip-to-fiber integration, which wastes samples and limits scalability.…”