Publications by authors named "Moritz Kleinert"

Mass-deployable implementations for quantum communication require compact, reliable, and low-cost hardware solutions for photon generation, control and analysis. We present a fiber-pigtailed hybrid photonic circuit comprising nonlinear waveguides for photon-pair generation and a polymer interposer reaching of pump suppression and photon separation based on a polarizing beam splitter with polarization extinction ratio. The optical stability of the hybrid assembly enhances the quality of the entanglement, and the efficient background suppression and photon routing further reduce accidental coincidences.

View Article and Find Full Text PDF

A lab-on-a-chip multichannel sensing platform for biomedical analysis based on optical silicon nitride (SiNx) microring-resonators (MRR) was established. The resonators were surface functionalized and finally combined with a microfluidic chamber for validation using an avidin-biotin ligand-binding assay. The results with a limit of detection (LOD) of 2.

View Article and Find Full Text PDF

A reliable, but cost-effective generation of single-photon states is key for practical quantum communication systems. For real-world deployment, waveguide sources offer optimum compatibility with fiber networks and can be embedded in hybrid integrated modules. Here, we present what we believe to be the first chip-size fully integrated fiber-coupled heralded single photon source (HSPS) module based on a hybrid integration of a nonlinear lithium niobate waveguide into a polymer board.

View Article and Find Full Text PDF

For wireless networks beyond 5G, directivity and reconfigurability of antennas are highly relevant. Therefore, we propose a linear antenna array based on photodiodes operating at 300 GHz, and an optical phased array based on polymer waveguides to orchestrate the antennas. Due to its low thermal conductivity and high thermo-optical coefficient, the polymer chip enables highly efficient and crosstalk-free phase shifting.

View Article and Find Full Text PDF

We fabricated a simple sensor system for qualitative analysis of glycan-mediated interactions. Our main aim was to establish a ronbbust system that allowes drop-tests without complex fluidics. The test system should be usable in routine analytics in the future and bear sufficient sensitivity to detect binding events in the nanomolar range.

View Article and Find Full Text PDF

In this Letter, we experimentally demonstrate a monolithic integration of two vertically rolled-up microtube resonators (VRUMs) on polymer-based 1×5 multimode interference waveguides to achieve 3D multi-channel coupling. In this configuration, different sets of resonant modes are simultaneously excited at S-, C-, and L- telecom bands, demonstrating an on-chip multiplexing, based on a vertical-coupling configuration. Moreover, the resonant wavelength tuning and consequently the overlapping of resonant modes are accomplished via covering the integrated VRUMs by liquid.

View Article and Find Full Text PDF

Microtubular optical resonators are monolithically integrated on photonic chips to demonstrate optofluidic functionality. Due to the compact subwavelength-thin tube wall and a well-defined nanogap between polymer photonic waveguides and the microtube, excellent optical coupling with extinction ratios up to 32 dB are observed in the telecommunication relevant wavelength range. For the first time, optofluidic applications of fully on-chip integrated microtubular systems are investigated both by filling the core of the microtube and by the microtube being covered by a liquid droplet.

View Article and Find Full Text PDF

We present a fiber-coupled transceiver for THz time-domain spectroscopy, which combines an emitter and a receiver on a single photoconductive chip. With a bandwidth of 4.5 THz and a peak dynamic range larger than 70 dB, it allows for THz reflection measurements under normal incidence.

View Article and Find Full Text PDF

We demonstrate full integration of vertical optical ring resonators with silicon nanophotonic waveguides on silicon-on-insulator substrates to accomplish a significant step toward 3D photonic integration. The on-chip integration is realized by rolling up 2D differentially strained TiO(2) nanomembranes into 3D microtube cavities on a nanophotonic microchip. The integration configuration allows for out-of-plane optical coupling between the in-plane nanowaveguides and the vertical microtube cavities as a compact and mechanically stable optical unit, which could enable refined vertical light transfer in 3D stacks of multiple photonic layers.

View Article and Find Full Text PDF

An external cavity laser is demonstrated based on the hybrid integration of an InP-based gain element, a half-wave plate, and thermally drivable polymer waveguide circuits. The laser has one oscillation region but two outputs for TE and TM emissions. The central wavelength can be tuned 20 nm at 20 mW heater electrical power.

View Article and Find Full Text PDF