3D printed micro-optics for quantum technology: Optimised coupling of single quantum dot emission into a single-mode fibre

Quantum Dot Single-Photon Emission Coupled into Single-Mode Fibers with 3D Printed Micro-Objectives

“…It is noticeable that in addition to the sample shown, another QD-microlens was fibercoupled, resulting in a comparable value for the in-coupling efficiency from the QD-microlens into the fiber of 24% ± 2% (see the supplementary material). In addition, in the validation of the coupling system, 38 the coupling efficiency of 26% ± 5% was measured, which is a good value for low-dimensional single-mode fiber coupling, even if there is a large discrepancy to the simplified ray tracing model mentioned above. We expect to reach significantly higher fiber-coupling efficiencies in the future, e.g., by using, for instance, near-field coupling in the circular Bragg grating single-photon sources.…”

“…Details on the design of the TPL written lenses, its optimization, and its relationship to the achievable photoluminescence enhancement are given in the supplementary material and in Ref. 38. For these optimization measurements, high-precision low temperature deterministic lithography was used 43 marking the emitter for further room temperature fabrication.…”

Superconducting nanowire single-photon detector with 3D-printed free-form microlenses

“…The critical temperature of the samples amounts to Tc = 12 K. The 3D-printed microlenses were fabricated in situ by multi-photon lithography [22,26,27] G  along with a 1 dB decay at a tilt angle of 1dB 2.9   . For fully automated 3D lithography, we use markers in the direct vicinity of each detector along with techniques for detection of the chip height and tilt.…”

Direct (3+1)D laser writing of graded-index optical elements

“…Additive manufacturing by two-photon polymerization (TPP) is rapidly becoming an important hybridization tool among various photonic integrated platforms due to its high versatility. Neither photo-masks nor etching are required for additive manufacturing, and intricate dielectric photonic structures can accommodate a wide range of host platforms, for example quantum systems [1], silicon photonics [2] or the tip of fibers [3]. Crucially, this fabrication technology is largely agnostic to particularities of such host platforms.…”