We present a study of single nanoparticle detection using parity-time (PT) symmetric whispering-gallery mode (WGM) resonators. Our theoretical model and numerical simulations show that, with balanced gain and loss, the PT-symmetri

We study light propagation through cyclic arrays, composed by copies of a given PT-symmetric dimer, using a group theoretical approach and finite element modeling. The theoretical mode-coupling analysis suggests the use of these d

Parity–time (PT) symmetry has been demonstrated in the frame of classic optics. Its applications in laser science have resulted in unconventional control and manipulation of resonant modes. PT-symmetric periodic circular Bragg las

This special issue is dedicated to the emerging field of non-Hermitian photonics of complex media, with emphasis on PT-symmetric optical structures. In particular, the papers highlight the variety of applications being considered

Strong nonlinearity of plasmonic metamaterials can be designed near their effective plasma frequency in the epsilon-near-zero (ENZ) regime. We explore the realization of an all-optical modulator based on the Au nonlinearity using

Nonlinear silicon photonics has shown an ability to generate, manipulate, and detect optical signals on an ultracompact chip at a potential low cost. There are still barriers hindering its development due to essential material lim

A polarization-diversity loop with a silicon waveguide with a lateral p-i-n diode as a nonlinear medium is used to realize polarization insensitive four-wave mixing. Wavelength conversion of seven dual-polarization 16-quadrature a

We demonstrate significantly improved performance of a microwave true time delay line based on an integrated optical frequency comb source. The broadband micro-comb (over 100 nm wide) features a record low free spectral range (FSR

In this paper, we report the experimental characterization of highly nonlinear GeSbS chalcogenide glass waveguides. We used a single-beam characterization protocol that accounts for the magnitude and sign of the real and imaginary

We introduce a nanoscale photonic platform based on gallium phosphide. Owing to the favorable material properties, peak power intensity levels of 50 GW/cm2 are safely reached in a suspended membrane. Consequently, the field enhanc

CMOS platforms with a high nonlinear figure of merit are highly sought after for high photonic quantum efficiencies, enabling functionalities not possible from purely linear effects and ease of integration with CMOS electronics. S

Dielectric nanocavities are emerging as a versatile and powerful tool for the linear and nonlinear manipulation of light at the nanoscale. In this work, we exploit the effective coupling of electric and toroidal modes in AlGaAs na

We experimentally demonstrate the generation of highly coherent Type-II micro-combs based on a micro-resonator nested in a fiber cavity loop, known as the filter-driven four wave mixing (FD-FWM) laser scheme. In this system, the f

We report the fabrication and characterization of silicon carbide microdisks on top of silicon pillars suited for applications from near- to mid-infrared. We probe 10 μm diameter disks with different under-etching depths, from 4 μ

Typically, photonic waveguides designed for nonlinear frequency conversion rely on intuitive and established principles, including index guiding and bandgap engineering, and are based on simple shapes with high degrees of symmetry

The field of nonlinear photonics is in full development. This special issue of Photonics Research takes you through the current issues of this fast-growing field of research, drawing on the current state of the art and seeking, th

A monolithic integrated few-mode transmitter comprising of two directly modulated distributed feedback lasers and a multimode-interference-coupler-based mode converter-multiplexer with 66% mode conversion efficiency was designed a

A band-gap-tailored random laser with a wide tunable range and low threshold through infrared radiation is demonstrated. When fluorescent dyes are doped into the liquid crystal and heavily doped chiral agent system, we demonstrate

The mode-locked laser diode has emerged as a promising candidate as a signal source for photonic radar systems, wireless data transmission, and frequency comb spectroscopy. They have the advantages of small size, low cost, high re

We show that a metasurface composed of a subwavelength metallic slit array embedded in an asymmetric dielectric environment can exhibit either extraordinary optical transmission (EOT) or extraordinary optical diffraction (EOD). Th

Dual combs are an emerging tool to obtain unprecedented resolution, high sensitivity, ultrahigh accuracy, broad bandwidth, and ultrafast data updating rate in the fields of molecular spectroscopy, optical metrology, as well as opt

We report an all-fiber, all-polarization maintaining (PM) source of widely tunable (1800–2000 nm) ultrashort pulses based on the amplification of coherent self-frequency-shifted solitons generated in a highly nonlinear fiber pumpe

A spectrally flat mid-infrared supercontinuum (MIR-SC) spanning 2.8–3.9 μm with a maximum output power of 411 mW was generated in a holmium-doped ZBLAN fiber amplifier (HDZFA). A broadband fiber-based SC covering the 2.4–3.2 μm re

Aggregation of metal nanoparticles plays an important role in surface enhanced Raman scattering (SERS). Here, a strategy of dynamically aggregating/releasing gold nanoparticles is demonstrated using a gold-nanofilm coated nanofibe

Although plasmonic nanostructure has attracted widespread research interest in recent years, it is still a major challenge to realize large-scale active plasmonic nanostructure operation in the visible optical frequency. Herein, w

This paper reports the experimental realization of efficiently sorting vector beams by polarization topological charge (PTC). The PTC of a vector beam can be defined as the repetition number of polarization state change along the

We experimentally demonstrated a method of generating continuously wavelength-switchable optical vortex beams (OVBs) in an all-fiber laser. A polarization-dependent microknot resonator (MKR) functions as comb filter and accounts f

Vector beams with spatially variant polarization have attracted much attention in recent years, with potential applications in both classical optics and quantum optics. In this work, we study a polarization selection of spatial in

As a highly entangled quantum network, the cluster state has the potential for greater information capacity and use in measurement-based quantum computation. Here, we report generating a continuous-variable quadripartite “square”

Conventionally, metallic nanostructures are used for surface-enhanced Raman spectroscopy (SERS), but recently there has been increasing interest in the enhancement of Raman scattering from dielectric substrates due to their improv

The chimera state is the concurrent combination of synchronous and incoherent oscillations in a set of identical oscillators. In this study, we demonstrate the states for optical nanoresonators where the oscillators are designed b

In silicon photonics, the carrier depletion scheme has been the most commonly used mechanism for demonstrating high-speed electro-optic modulation. However, in terms of phase modulation efficiency, carrier-accumulation-based devic

With the rapidly increasing bandwidth requirements of optical communication networks, compact and low-cost large-scale optical switches become necessary. Silicon photonics is a promising technology due to its small footprint, cost

We demonstrate the suppression of soft X-ray high harmonics generated by two-color laser pulses interacting with Ne gas in a gas cell. We show that harmonic suppression can occur at the proper combination of the propagation distan

We propose and experimentally demonstrate a recorded 1-m bidirectional 20.231-Gbit/s tricolor R/G/B laser diode (LD) based visible-light communication (VLC) system supporting signal remodulation. In the signal remodulation system,

A nanowire (NW) structure provides an alternative scheme for deep ultraviolet light emitting diodes (DUV-LEDs) that promises high material quality and better light extraction efficiency (LEE). In this report, we investigate the in