Related papers: Coherent two-octave-spanning supercontinuum genera…

Owing to the discrete frequency spectrum of whispering gallery resonators (WGRs), the resonance and phase-matching conditions for the interacting waves in the case of second-harmonic generation (SHG) cannot generally be fulfilled…

A high-resolution broad-spectral-bandwidth spectrometer on a chip would create new opportunities for gas-phase molecular fingerprinting, especially in environmental sensing. A resolution high enough to observe transitions at atmospheric…

Bound states in the continuum (BICs), a concept from quantum mechanics, are ubiquitous physical phenomena where waves will be completely locked inside physical systems without energy leaky. Such a physical phenomenon in optics will provide…

We discuss a novel method for generating octave-spanning supercontinua and few-cycle pulses in the important mid-IR wavelength range. The technique relies on strongly phase-mismatched cascaded second-harmonic generation (SHG) in mid-IR…

Nanophotonic entangled-photon sources are a critical building block of chip-scale quantum photonic architecture and have seen significant development over the past two decades. These sources generate photon pairs that typically span over a…

Second harmonic generation (SHG) is a nonlinear optical response arising exclusively from broken inversion symmetry in the electric-dipole limit. Recently, SHG has attracted widespread interest as a versatile and noninvasive tool for…

We demonstrate waveguide-integrated superconducting nanowire single-photon detectors on thin-film lithium niobate (LN). Using a 250 um-long NbN superconducting nanowire lithographically defined on top of a 125 um-long LN nanowaveguide,…

Nonlinear frequency mixing is of critical importance in extending the wavelength range of optical sources. It is also indispensable for emerging applications such as quantum information and photonic signal processing. Conventional lithium…

A fully stabilized frequency comb is essential for precision metrology and coherent optical synthesis. However, fully-stabilized frequency combs generally require separate stages for supercontinuum generation (SCG) and self-referencing,…

Nonlinear optics in whispering-gallery-mode (WGM) microresonators have attracted much attention. Owing to strong confinement of the light in a small volume, a WGM microresonator can dramatically boost the strength of light field, giving…

An anomalous flat-band dispersion provided by a degenerate band edge (DBE) of longitudinal optical modes in a double-grating waveguide is used to enhance second-harmonic generation (SHG). The DBE is a fourth-order exceptional point…

We propose and demonstrate subwavelength grating (SWG) metamaterial waveguides and ring resonators on a silicon nitride platform for the first time. The SWG waveguide is engineered such that a large overlap of 53% of the Bloch mode with the…

A broadband visible blue-to-red, 10 GHz repetition rate frequency comb is generated by combined spectral broadening and triple-sum frequency generation in an on-chip silicon nitride waveguide. Ultra-short pulses of 150 pJ pulse energy,…

Thin-film lithium niobate (TFLN) is an emerging platform for compact, low-power nonlinear-optical devices, and has been used extensively for near-infrared frequency conversion. Recent work has extended these devices to mid-infrared…

Quadratic optical parametric processes form the foundation for a variety of applications related to classical and quantum frequency conversion, which have attracted significant interest recently in on-chip implementation. These processes…

We present a simple method for fully-stabilized mid-infrared optical frequency comb generation based on single-pass femtosecond optical parametric generation that is seeded by a continuous-wave laser. We have implemented the method in a…

High harmonic generation (HHG) is a powerful probe of electron dynamics on attosecond to femtosecond timescales and has been successfully used to detect electronic and structural changes in solid-state quantum materials, including…

Optical materials with centrosymmetry, such as silicon and germanium, are unfortunately absent of second-order nonlinear optical responses, hindering their developments in efficient nonlinear optical devices. Here, a design with an array of…

We demonstrate second order optical nonlinearity in aluminum nitride on insulator substrates. Using sputter-deposited aluminum nitride thin films we realize nanophotonic waveguides coupled to micro-ring resonators that simultaneously…

Low-loss single-mode optical waveguide fabrication process in extra-white soda-lime glass is demonstrated. Waveguiding structures are formed in bulk substrates employing femtosecond laser writing technology. The combination of a slit…