Radiation source assemblies and methods for generating broadened radiation by spectral broadening. A radiation source assembly includes a pump source configured to emit modulated pump radiation at one or more wavelengths. The assembly further has an optical fiber configured to receive the modulated pump radiation emitted by the pump source, the optical fiber including a hollow core extending along at least part of a length of the fiber. The hollow core is configured to guide the received radiation during propagation through the fiber. The radiation emitted by the pump source includes first radiation at a pump wavelength, and the pump source is configured to modulate the first radiation for stimulating spectral broadening in the optical fiber.

Examples of the present disclosure include the use of a topological system including an array of coupled ring resonators that exhibits topological edge states to generate frequency combs and temporal dissipative Kerr solitons. The topological edge states constitute a travelling-wave super-ring resonator causing generation of at least coherent nested optical frequency combs, and self-formation of nested temporal solitons that are robust against defects in the array at a mode efficiency exceeding 50%.

A topological photonic system configured as a robust source of indistinguishable photons pairs with tunable spectral correlations. The system includes a two-dimensional silicon-photonic ring resonator array configured to implement an anomalous-quantum Hall model that exhibits topologically robust edge states. Linear dispersion of the edge states ensures efficient and robust phase matching and tunability of the spectral bandwidth of photon pairs generated via spontaneous four-wave mixing. Spectral tunability is manifested in the temporal correlations in the Hong-Ou-Mandel interference between photons. The generated photon pairs are energy-time entangled.

Recent remarkable progress in wave-front shaping has enabled control of light propagation inside linear media to focus and image through scattering objects. In particular, light propagation in multimode fibers comprises complex intermodal interactions and rich spatiotemporal dynamics. Control of physical phenomena in multimode fibers and its applications is in its infancy, opening opportunities to take advantage of complex mode interactions. Various embodiments of the present technology provide wave-front shaping for controlling nonlinear phenomena in multimode fibers. Using a spatial light modulator at the fiber's input and a genetic algorithm optimization, some embodiments control a highly nonlinear stimulated Raman scattering cascade and its interplay with four wave mixing via a flexible implicit control on the superposition of modes that are coupled into the fiber.

An optical device has a first optical layer with a first dispersion response as a first function of wavelength. A second optical layer has a second dispersion response as a function of wavelength that is different than the first function. A separating layer is located between the first and second optical layers and has a lower refractive index than the first layer and the second layer. A thickness of the separating layer is selected such that the first and second dispersion responses combine to create an anomalous dispersion about a target wavelength. The anomalous dispersion results in the optical device emitting a wideband coherent optical output about the target wavelength in response to an optical input at the target wavelength.

Systems and methods in accordance with embodiments of the invention implement all-microwave stabilized microresonator-based optical frequency comb. In one embodiment, an all-microwave stabilized microresonator-based optical frequency comb includes: an optical pump configured to generate pulses of light; a microresonator including an input configured to receive pulses generated by an optical pump and an output configured to generate an optical frequency comb signal characterized by frep and ξ; where frep describes spacing of frequency components in the optical frequency comb; where the optical frequency comb includes a primary comb and a plurality of subcombs and ξ is a frequency offset between subcombs; and two phase locked loops that phase lock frep and ξ to low noise microwave oscillators by modulating output power and pump frequency of the optical pump.

Techniques disclosed herein relate to photon sources with high spectral purity and high brightness. In one embodiment, a photon-pair source includes a pump waveguide, a first resonator coupled to the pump waveguide to couple pump photons from the pump waveguide into the first resonator, a second resonator coupled to the first resonator, and an output waveguide coupled to the second resonator. The second resonator is configured to convert the pump photons into photon pairs. The second resonator and the first resonator are configured to cause a coupling-induced resonance splitting in the second resonator or the first resonator. The second resonator and the output waveguide are configured to couple the photon pairs from the second resonator into the output waveguide. In some embodiments, the photo-pair source includes one or more tuners for tuning at least one of the first resonator or the second resonator.

A system for generating clock signals for a photonic quantum computing system includes a pump photon source configured to generate a plurality of pump photon pulses at a first repetition rate, a waveguide optically coupled to the pump photon source, and a photon-pair source optically coupled to the first waveguide. The system also includes a photodetector optically coupled to the photon-pair source and configured to generate a plurality of electrical pulses in response to detection of at least a portion of the plurality of pump photon pulses at the first repetition rate and a clock generator coupled to the photodetector and configured to convert the plurality of electrical pulses into a plurality of clock signals at the first repetition rate.

In some implementations, a monolithic optical fiber may comprise a tapered core having a first diameter at an input end and a second diameter at an output end. The tapered core may comprise a first tapered region at the input end, a second tapered region at the output end, and a central region having a constant diameter that is larger than the first diameter and the second diameter. The first tapered region expands monotonically from the first diameter to the constant diameter of the central region along a length of the first tapered region, and the second tapered region contracts monotonically from the constant diameter of the central region to the second diameter along a length of the second tapered region. The monolithic optical fiber may be used as a delivery fiber to deliver a laser beam from a fiber laser engine to a process head.

An optical ring resonator that includes a closed loop core, a cladding layer, and one or more bus waveguides. The closed loop core is disposed in the cladding layer and is As.sub.2Se.sub.3 glass. The one or more bus waveguides are disposed in the cladding layer and are optically coupled to the closed loop core. The closed loop core has a zero-dispersion wavelength within a telecommunication wavelength band. The closed loop core has a plurality of resonant modes, including a zero-dispersion resonant mode corresponding with the zero-dispersion wavelength and a plurality of paired resonant modes. Further, the closed loop core has a phase matching bandwidth extending greater than ±40 nm from the zero-dispersion wavelength.