TY - JOUR AB - The achievement of a flat metasurface has realized extraordinary control over light–matter interaction at the nanoscale, enabling widespread use in imaging, holography, and biophotonics. However, three-dimensional metasurfaces with the potential to provide additional light–matter manipulation flexibility attract only little interest. Here, we demonstrate a three-dimensional metasurface scheme capable of providing dual phase control through out-of-plane plasmonic resonance of L-shape antennas. Under circularly polarized excitation at a specific wavelength, the L-shape antennas with rotating orientation angle act as spatially variant three-dimensional tilted dipoles and are able to generate desire phase delay for different polarization components. Generalized Snell's law is achieved for both in-plane and out-of-plane dipole components through arranging such L-shape antennas into arrays. These three-dimensional metasurfaces suggest a route for wavefront modulation and a variety of nanophotonic applications. AU - Li, Tianyou AU - Chen, Yanjie AU - Wang, Yongtian AU - Zentgraf, Thomas AU - Huang, Lingling ID - 43421 IS - 14 JF - Applied Physics Letters KW - Physics and Astronomy (miscellaneous) SN - 0003-6951 TI - Three-dimensional dipole momentum analog based on L-shape metasurface VL - 122 ER - TY - JOUR AB - Optical geometric phase encoded by in-plane spatial orientation of microstructures has promoted the rapid development of numerous functional meta-devices. However, pushing the concept of the geometric phase toward the acoustic community still faces challenges. In this work, we utilize two acoustic nonlocal metagratings that could support a direct conversion between an acoustic plane wave and a designated vortex mode to obtain the acoustic geometric phase, in which an orbital angular momentum conversion process plays a vital role. In addition, we realize the acoustic geometric phases of different orders by merely varying the orientation angle of the acoustic nonlocal metagratings. Intriguingly, according to our developed theory, we reveal that the reflective acoustic geometric phase, which is twice the transmissive one, can be readily realized by transferring the transmitted configuration to a reflected one. Both the theoretical study and experimental measurements verify the announced transmissive and reflective acoustic geometric phases. Moreover, the reconfigurability and continuous phase modulation that covers the 2π range shown by the acoustic geometric phases provide us with the alternatives in advanced acoustic wavefront control. AU - Liu, Bingyi AU - Zhou, Zhiling AU - Wang, Yongtian AU - Zentgraf, Thomas AU - Li, Yong AU - Huang, Lingling ID - 31480 IS - 21 JF - Applied Physics Letters KW - Physics and Astronomy (miscellaneous) SN - 0003-6951 TI - Experimental verification of the acoustic geometric phase VL - 120 ER - TY - JOUR AB - Recently, microcavities with anisotropic materials were shown to be able to create bands with non-zero local Berry curvature. The anisotropic refractive index of the cavity layer is believed to be critical in opening an energy gap at the tilted Dirac points. In this work, we show that the anticrossing between a cavity mode and a Bragg mode can also be realized within an empty microcavity without any birefringent materials in the cavity layer. Nondispersive bands are observed within the energy gap due to the particular refractive index distribution of the sample. The intrinsic TE-TM splitting and XY splitting of DBR mirrors induce the squeezing of the cavity modes in momentum space, so that the nondispersive bands are tilted and spin-dependent. Our results pave the way to investigate interesting physical phenomena of photonic modes close to or in the nondispersive bands without anisotropic cavity layers. AU - Gao, Ying AU - Li, Yao AU - Ma, Xuekai AU - Gao, Meini AU - Dai, Haitao AU - Schumacher, Stefan AU - Gao, Tingge ID - 36414 IS - 20 JF - Applied Physics Letters KW - Physics and Astronomy (miscellaneous) SN - 0003-6951 TI - Tilting nondispersive bands in an empty microcavity VL - 121 ER - TY - JOUR AU - Gao, Ying AU - Li, Yao AU - Ma, Xuekai AU - Gao, Meini AU - Dai, Haitao AU - Schumacher, Stefan AU - Gao, Tingge ID - 34094 IS - 20 JF - Applied Physics Letters KW - Physics and Astronomy (miscellaneous) SN - 0003-6951 TI - Tilting nondispersive bands in an empty microcavity VL - 121 ER - TY - JOUR AB - Spontaneous Raman spectroscopy (SR) is a versatile method for analysis and visualization of ferroelectric crystal structures, including domain walls. Nevertheless, the necessary acquisition time makes SR impractical for in situ analysis and large scale imaging. In this work, we introduce broadband coherent anti-Stokes Raman spectroscopy (B-CARS) as a high-speed alternative to conventional Raman techniques and demonstrate its benefits for ferroelectric domain wall analysis. Using the example of poled lithium niobate, we compare the spectral output of both techniques in terms of domain wall signatures and imaging capabilities. We extract the Raman-like resonant part of the coherent anti-Stokes signal via a Kramers–Kronig-based phase retrieval algorithm and compare the raw and phase-retrieved signals to SR characteristics. Finally, we propose a mechanism for the observed domain wall signal strength that resembles a Čerenkov-like behavior, in close analogy to domain wall signatures obtained by second-harmonic generation imaging. We, thus, lay here the foundations for future investigations on other poled ferroelectric crystals using B-CARS. AU - Reitzig, Sven AU - Hempel, Franz AU - Ratzenberger, Julius AU - Hegarty, Peter A. AU - Amber, Zeeshan H. AU - Buschbeck, Robin AU - Rüsing, Michael AU - Eng, Lukas M. ID - 47982 IS - 16 JF - Applied Physics Letters KW - Physics and Astronomy (miscellaneous) SN - 0003-6951 TI - High-speed hyperspectral imaging of ferroelectric domain walls using broadband coherent anti-Stokes Raman scattering VL - 120 ER - TY - JOUR AB - In our work, we have engineered low capacitance single quantum dot photodiodes as sensor devices for the optoelectronic sampling of ultrafast electric signals. By the Stark effect, a time-dependent electric signal is converted into a time-dependent shift of the transition energy. This shift is measured accurately by resonant ps laser spectroscopy with photocurrent detection. In our experiments, we sample the laser synchronous output pulse of an ultrafast CMOS circuit with high resolution. With our quantum dot sensor device, we were able to sample transients below 20 ps with a voltage resolution in the mV-range. AU - Widhalm, Alex AU - Krehs, Sebastian AU - Siebert, Dustin AU - Sharma, Nand Lal AU - Langer, Timo AU - Jonas, Björn AU - Reuter, Dirk AU - Thiede, Andreas AU - Förstner, Jens AU - Zrenner, Artur ID - 27099 JF - Applied Physics Letters KW - tet_topic_qd SN - 0003-6951 TI - Optoelectronic sampling of ultrafast electric transients with single quantum dots VL - 119 ER - TY - JOUR AU - Wang, D. Q. AU - Reuter, Dirk AU - Wieck, A. D. AU - Hamilton, A. R. AU - Klochan, O. ID - 17433 JF - Applied Physics Letters SN - 0003-6951 TI - Two-dimensional lateral surface superlattices in GaAs heterostructures with independent control of carrier density and modulation potential ER - TY - JOUR AU - Riha, Christian AU - Buchholz, Sven S. AU - Chiatti, Olivio AU - Wieck, Andreas D. AU - Reuter, Dirk AU - Fischer, Saskia F. ID - 17995 JF - Applied Physics Letters SN - 0003-6951 TI - Excess noise in Al x Ga 1 − xAs/GaAs based quantum rings ER - TY - JOUR AU - Mukherjee, Amlan AU - Widhalm, Alex AU - Siebert, Dustin AU - Krehs, Sebastian AU - Sharma, Nandlal AU - Thiede, Andreas AU - Reuter, Dirk AU - Förstner, Jens AU - Zrenner, Artur ID - 17322 JF - Applied Physics Letters KW - tet_topic_qd SN - 0003-6951 TI - Electrically controlled rapid adiabatic passage in a single quantum dot VL - 116 ER - TY - JOUR AU - Vergyris, Panagiotis AU - Babin, Charles AU - Nold, Raphael AU - Gouzien, Elie AU - Herrmann, Harald AU - Silberhorn, Christine AU - Alibart, Olivier AU - Tanzilli, Sébastien AU - Kaiser, Florian ID - 40271 IS - 2 JF - Applied Physics Letters KW - Physics and Astronomy (miscellaneous) SN - 0003-6951 TI - Two-photon phase-sensing with single-photon detection VL - 117 ER - TY - JOUR AB - We report on the coherent phase manipulation of quantum dot excitons by electric means. For our experiments, we use a low capacitance single quantum dot photodiode which is electrically controlled by a custom designed SiGe:C BiCMOS chip. The phase manipulation is performed and quantified in a Ramsey experiment, where ultrafast transient detuning of the exciton energy is performed synchronous to double pulse p/2 ps laser excitation. We are able to demonstrate electrically controlled phase manipulations with magnitudes up to 3p within 100 ps which is below the dephasing time of the quantum dot exciton. AU - Widhalm, Alex AU - Mukherjee, Amlan AU - Krehs, Sebastian AU - Sharma, Nandlal AU - Kölling, Peter AU - Thiede, Andreas AU - Reuter, Dirk AU - Förstner, Jens AU - Zrenner, Artur ID - 3427 IS - 11 JF - Applied Physics Letters KW - tet_topic_qd SN - 0003-6951 TI - Ultrafast electric phase control of a single exciton qubit VL - 112 ER - TY - JOUR AU - Allgaier, Markus AU - Ansari, Vahid AU - Eigner, Christof AU - Quiring, Viktor AU - Ricken, Raimund AU - Donohue, John Matthew AU - Czerniuk, Thomas AU - Aßmann, Marc AU - Bayer, Manfred AU - Brecht, Benjamin AU - Silberhorn, Christine ID - 21029 JF - Applied Physics Letters SN - 0003-6951 TI - Streak camera imaging of single photons at telecom wavelength VL - 112 ER - TY - JOUR AU - Liu, Ning AU - Steinrück, Hans-Georg AU - Osvet, Andres AU - Yang, Yuyun AU - Schmuki, Patrik ID - 23630 JF - Applied Physics Letters SN - 0003-6951 TI - Noble metal free photocatalytic H2 generation on black TiO2: On the influence of crystal facets vs. crystal damage VL - 110 ER - TY - JOUR AU - Lafont, O. AU - Luk, S. M. H. AU - Lewandowski, P. AU - Kwong, N. H. AU - Leung, P. T. AU - Galopin, E. AU - Lemaitre, A. AU - Tignon, J. AU - Schumacher, Stefan AU - Baudin, E. AU - Binder, R. ID - 13361 JF - Applied Physics Letters SN - 0003-6951 TI - Controlling the optical spin Hall effect with light ER - TY - JOUR AU - Layes, V. AU - Monje, S. AU - Corbella, C. AU - Trieschmann, J. AU - de los Arcos de Pedro, Maria Teresa AU - von Keudell, A. ID - 22568 JF - Applied Physics Letters SN - 0003-6951 TI - Species transport on the target during high power impulse magnetron sputtering ER - TY - JOUR AU - Atorf, B. AU - Rasouli, H. AU - Nordendorf, G. AU - Wilkes, D. AU - Kitzerow, Heinz-Siegfried ID - 39674 IS - 8 JF - Applied Physics Letters KW - Physics and Astronomy (miscellaneous) SN - 0003-6951 TI - Near infrared Kerr effect and description of field-induced phase transitions in polymer-stabilized blue phase liquid crystals VL - 108 ER - TY - JOUR AB - We report the fabrication of periodically poled domain patterns in x-cut lithium niobate thin-film. Here, thin films on insulator have drawn particular attention due to their intrinsic waveguiding properties offering high mode confinement and smaller devices compared to in-diffused waveguides in bulk material. In contrast to z-cut thin film lithium niobate, the x-cut geometry does not require back electrodes for poling. Further, the x-cut geometry grants direct access to the largest nonlinear and electro-optical tensor element, which overall promises smaller devices. The domain inversion was realized via electric field poling utilizing deposited aluminum top electrodes on a stack of LN thin film/SiO2 layer/Bulk LN, which were patterned by optical lithography. The periodic domain inversion was verified by non-invasive confocal second harmonic microscopy. Our results show domain patterns in accordance to the electrode mask layout. The second harmonic signatures can be interpreted in terms of spatially, overlapping domain filaments which start their growth on the þz side. AU - Mackwitz, P. AU - Rüsing, Michael AU - Berth, Gerhard AU - Widhalm, A. AU - Müller, K. AU - Zrenner, Artur ID - 4237 IS - 15 JF - Applied Physics Letters SN - 0003-6951 TI - Periodic domain inversion in x-cut single-crystal lithium niobate thin film VL - 108 ER - TY - JOUR AU - Jostmeier, Thorben AU - Wecker, Tobias AU - Reuter, Dirk AU - As, Donat Josef AU - Betz, Markus ID - 7217 IS - 21 JF - Applied Physics Letters SN - 0003-6951 TI - Ultrafast carrier dynamics and resonant inter-miniband nonlinearity of a cubic GaN/AlN superlattice VL - 107 ER - TY - JOUR AU - Chen, J. C. H. AU - Klochan, O. AU - Micolich, A. P. AU - Das Gupta, K. AU - Sfigakis, F. AU - Ritchie, D. A. AU - Trunov, K. AU - Reuter, Dirk AU - Wieck, A. D. AU - Hamilton, A. R. ID - 7221 IS - 18 JF - Applied Physics Letters SN - 0003-6951 TI - Fabrication and characterisation of gallium arsenide ambipolar quantum point contacts VL - 106 ER - TY - JOUR AB - We report about the fabrication and analysis of high Q photonic crystal cavities with metallic Schottky-contacts. The structures are based on GaAs n-i membranes with an InGaAs quantum well in the i-region and nanostructured low ohmic metal top-gates. They are designed for photocurrent readout within the cavity and fast electric manipulations. The cavity structures are characterized by photoluminescence and photocurrent spectroscopy under resonant excitation. We find strong cavity resonances in the photocurrent spectra and surprisingly high Q-factors up to 6500. Temperature dependent photocurrent measurements in the region between 4.5K and 310K show an exponential enhancement of the photocurrent signal and an external quantum efficiency up to 0.26. AU - Quiring, W. AU - Al-Hmoud, M. AU - Rai, A. AU - Reuter, Dirk AU - Wieck, A. D. AU - Zrenner, Artur ID - 4331 IS - 4 JF - Applied Physics Letters SN - 0003-6951 TI - Photonic crystal cavities with metallic Schottky contacts VL - 107 ER -