Shaimaa I. Azzam, Krishnakali Chaudhuri, Alexei Lagutchev, Zubin Jacob, Young L., Vladimir M. Shalaev, Alexandra Boltasseva, and Alexander V. Kildishev. 1/27/2021.

Single and Multi-Mode Directional Lasing from Arrays of Dielectric Nanoresonators

. Laser & Photonics Reviews, 15.

Abstract The strong electric and magnetic resonances in dielectric subwavelength structures have enabled unique opportunities for efficient manipulation of light–matter interactions. Besides, the dramatic enhancement of nonlinear light–matter interactions near so-called bound states in the continuum (BICs) has recently attracted enormous attention due to potential advancements. However, the experimental realizations and the applications of high-Q factor resonances in dielectric resonances in the visible have thus far been considerably limited. In this work, the interplay of electric and magnetic dipoles in arrays of dielectric nanoresonators is explored. The experimental realization of high-Q factor resonances in the visible through the collective diffractive coupling of electric and magnetic dipoles is reported. It is also shown that coupling the Rayleigh anomaly of the array with the dipoles of the individual nanoresonators can result in the formation of different types of BICs. The resonances in the visible regime is utilized to achieve lasing action at room temperature with high spatial directionality and low threshold. Finally, multi-mode, directional lasing is experimentally demonstrated and the BIC-assisted lasing mode engineering in arrays of dielectric nanoresonators is studied. It is believed that the results enable a new range of applications in flat photonics through realizing on-chip controllable single and multi-wavelength micro-lasers.

Reza Baghdadi, Ekkehart Schmidt, Saman Jahani, Ilya Charaev, Michael G W Müller, Marco Colangelo, Di Zhu, Konstantin Ilin, Alexej D Semenov, Zubin Jacob, Michael Siegel, and Karl K Berggren. 2/2/2021.

Enhancing the performance of superconducting nanowire-based detectors with high-filling factor by using variable thickness

. Superconductor Science and Technology, 34.

Current crowding at bends of superconducting nanowire single-photon detector (SNSPD) is one of the main factors limiting the performance of meander-style detectors with large filling factors. In this paper, we propose a new concept to reduce the influence of the current crowding effect, a so-called variable thickness SNSPD, which is composed of two regions with different thicknesses. A larger thickness of bends in comparison to the thickness of straight nanowire sections locally reduces the current density and reduces the suppression of the critical current caused by current crowding. This allows variable thickness SNSPD to have a higher critical current, an improved detection efficiency, and decreased dark count rate in comparison with a standard uniform thickness SNSPD with an identical geometry and film quality.

Matthew van Niekerk, Saman Jahani, Justin Bickford, Pak Cho, Stephen Anderson, Gerald Leake, Daniel Coleman, Michael L. Fanto, Christopher C. Tison, Gregory A. Howland, Zubin Jacob, and Stefan F. Preble. 4/2021.

Two-dimensional extreme skin depth engineering for CMOS photonics

. J. Opt. Soc. Am. B, 38, 4, Pp. 1307-1316.

Extreme skin depth engineering (e-skid) can be applied to integratedphotonics to manipulate the evanescent field of a waveguide. Here wedemonstrate that e-skid can be implemented in two directions in order todeterministically engineer the evanescent wave allowing for denseintegration with enhanced functionalities. In particular, by increasingthe skin depth, we enable the creation of two-dimensional (2D) e-skiddirectional couplers with large gaps and operational bandwidth. Here weexperimentally validate 2D e-skid for integrated photonics in acomplementary metal--oxide semiconductor (CMOS) photonics foundry anddemonstrate strong coupling with a gap of 1.44 {\textmu}m.

Ashwin K. Boddeti, Jun Guan, Tyler Sentz, Xitlali Juarez, Ward Newman, Cristian L. Cortes, Teri W. Odom, and Zubin Jacob. 10/21/2021.

Long-Range Dipole-Dipole Interactions in a Plasmonic Lattice

. Nano letters, 22, Pp. 22–28.

Spontaneous emission of quantum emitters can be enhanced by increasing the local density of optical states, whereas engineering dipole–dipole interactions requires modifying the two-point spectral density function. Here, we experimentally demonstrate long-range dipole–dipole interactions (DDIs) mediated by surface lattice resonances in a plasmonic nanoparticle lattice. Using angle-resolved spectral measurements and fluorescence lifetime studies, we show that unique nanophotonic modes mediate long-range DDI between donor and acceptor molecules. We observe significant and persistent DDI strengths for a range of densities that map to ∼800 nm mean nearest-neighbor separation distance between donor and acceptor dipoles, a factor of ∼100 larger than free space. Our results pave the way to engineer and control long-range DDIs between an ensemble of emitters at room temperature.