光学
The principle of causality has long been mathematically associated with the frameworks of Titchmarsh's theorem and the Kramers--Kronig relations. While these relations arise naturally in the context of temporal system responses -- ensuring…
Hyperspectral fluorescence microscopy enables important biological and clinical applications, but conventional systems are bulky or require scanning, limiting temporal resolution and throughput. We introduce a computational snapshot…
Photonic waveguide design often requires repeated full-vector Maxwell eigenmode solves over wavelength, geometry, and material parameters. We present an adaptive eigenvector-continuation framework for accelerating and stabilizing these…
Nonlinear photonic time crystals (PTCs) can support solitons inside momentum k gaps, where the amplification of k gap modes is saturated by Kerr nonlinearity, forming spatially homogeneous but temporally localized excitations. Yet their…
We demonstrate that light propagation in reciprocal chiral photonic media admits a unified description in terms of an emergent Dirac structure in helicity space. Starting from Maxwell's equations, we reformulate the electromagnetic field as…
Multimode fibers (MMFs) offer a compact platform for imaging, sensing, and information transport, but their practical deployment is hindered by sensitivity to fiber perturbations, which alter modal coupling and invalidate conventional…
Interferometric sensors are ubiquitous in precision metrology, yet their performance is fundamentally limited by environmental noise and thermal drift. To achieve maximum sensitivity, these systems must be actively stabilized at the…
Metasurfaces often require complex lithography for dynamic optical control. To overcome this, we utilize a lithography-free, non-Hermitian planar metastack comprising a distributed Bragg reflector and a vanadium dioxide (VO2) thin film. By…
Self-injection locking (SIL) of a diode laser to a high quality-factor microresonator has recently become increasingly important in hybrid integrated photonics, providing access to compact sub-Hz linewidth lasers. It was also shown to…
The broadband gain characteristics of Co:MgF$_2$ were investigated to assess its potential as a gain medium for ultrashort-pulse amplification around the 2 $\mu$m spectral region. Single-pass gain measurements performed using femtosecond…
Infrared detection and visualization are essential for augmenting human perception across diverse fields, ranging from night vision to industrial inspection and bio-imaging. Conventional infrared cameras are often hindered by high cost,…
Near-infrared (NIR) imaging has emerged as an important technology for night vision, remote sensing, and biological imaging, yet conventional array-detector-based systems are often limited by insufficient sensitivity, high cost, and…
Microresonator Kerr solitons are promising candidates for the realization of miniaturized on-chip optical frequency combs. For specific system parameters, these solitons are associated with oscillatory instabilities, leading to breathing…
Optical antennas are widely used to localize electromagnetic fields far below the diffraction limit, enabling enhanced light-matter interactions across nanophotonics. Yet the regime in which optical confinement approaches the electronic de…
This report presents experimental measurements of coupling efficiency and laser-induced damage thresholds for a polarization-maintaining (PM) fiber patchcord with integrated end caps, evaluated at 532 nm using a compact actively Q-switched…
We investigate the complete dynamical pathway of photon-electron interactions involved in two-photon absorption (TPA) in a silicon nanowire waveguide using three independent high-speed measurement techniques. These methods probe different…
This work is a generalization of our previous study [arXiv:2406.17944], which dealt with the coherent and incoherent combination of linearly polarized Gaussian laser beams operating in continuous-wave mode under a $2\pi$ focusing…
We study the transport of light through dense opaque anisotropic metamaterials consisting of oriented nanowires. The nanowires consist of polymer photoresist that is structured by direct laser writing (DLW) with two-photon induced…
Nonreciprocal systems enable asymmetric energy transport and suppress backscattering, giving rise to unconventional wave phenomena. Here, we show that nonreciprocal cavities based on unidirectional waveguides exhibit a continuous modal…
Temporal boundaries in time-modulated media provide a powerful route toward wave manipulation beyond conventional spatial boundaries. Here, we investigate nonlinear temporal boundaries generated by interaction quenches in a synthetic…