Nonlinear Čerenkov Radiation in Nonlinear Photonic Crystal Waveguides

Abstract

We study nonlinear Cerenkov radiation generated from a nonlinear photonic crystal waveguide where the nonlinear susceptibility tensor is modulated by the ferroelectric domain. Nonlinear polarization driven by an incident light field may emit coherently harmonic waves at new frequencies along the direction of Cerenkov angles. Multiple radiation spots with different azimuth angles are simultaneously exhibited from such a hexagonally poled waveguide. A scattering involved nonlinear Cerenkov arc is also observed for the first time. Cerenkov radiation associated with quasi-phase matching leads to these novel nonlinear phenomena.

Quantum Čerenkov Radiation: Spectral Cutoffs and the Role of Spin and Orbital Angular Momentum

“…Namely, it can also occur for classical charge distributions having a well-defined spread angle θ i , as well as in analogs of the Čerenkov effect in other areas of physics (for example, see Refs. [13,14]; similar conditions could be designed in other systems analogous to ČR [8][9][10][11][12][13][14][15][16][17][18][19]21,22]). In either case, the cone splitting we show here is uniquely tied to the shape of the incoming electron wave packet (or the charge distribution in a classical electron beam), and it is independent of material properties that can cause other kinds of cone splittings [50].…”

“…Since its discovery, the Čerenkov effect has become a fundamental part of many fields [2]: Devices like the ring-imaging Čerenkov detector are used for cosmic radiation measurements [3,4], while other implications also suggest novel acceleration methods [5], and even an unusual imaging tool in biology [6,7]. Because of the fundamental nature of ČR, it is found in many different physical systems, such as in nonlinear optics [8][9][10][11], it is used in the design of quantum cascade lasers [12], and it is predicted to yield the generation of entangled photon pairs [13,14]. Other kinds of ČR were found in photonic crystals [15,16], tunable light sources [17], coherently driven ultracold atomic gas [18], and recently even in active gain medium [19].…”

Fourth-harmonic generation via nonlinear diffraction in a 2D LiNbO3 nonlinear photonic crystal from mid-IR ultrashort pulses

“…Second and third harmonics emerging at external angles of 23.82°and 36.75°result from nonlinearČerenkov and Bragg diffractions, respectively. Three pathways of fourth-harmonic generation are observed at external angles of 14.21°, 36.5°, and 53.48°, with the first one resulting from nonlinearČerenkov diffraction, and the other two harmonics are generated via different cascaded processes.OCIS codes: 190.4420, 190.2620, 050.1940. doi: 10.3788/COL201715.051901.When a monochromatic wave passes through a homogeneous medium with its second-order nonlinear susceptibility varying in some regions, e.g., χ ð2Þ in a nonlinear photonic crystal (NPC), nonlinear diffraction can be detected for the harmonic rings or spots of the input fundamental wave [1][2][3][4][5][6] . Nonlinear diffraction, which is based on phase matching, includes nonlinearČerenkov diffraction (NCD), nonlinear Raman-Nath diffraction (NRND), and nonlinear Bragg diffraction (NBD).…”

“…When a monochromatic wave passes through a homogeneous medium with its second-order nonlinear susceptibility varying in some regions, e.g., χ ð2Þ in a nonlinear photonic crystal (NPC), nonlinear diffraction can be detected for the harmonic rings or spots of the input fundamental wave [1][2][3][4][5][6] . Nonlinear diffraction, which is based on phase matching, includes nonlinearČerenkov diffraction (NCD), nonlinear Raman-Nath diffraction (NRND), and nonlinear Bragg diffraction (NBD).…”

Dual-wavelength laser with topological charge

“…It is motivating to investigate whether the simultaneous emission of different photons is possible. The lasers with different photons should be an efficient tool for study the interaction of photons and conservation of optical angular momentum 13,14 and should have promising applications in the transferring torque because the interacted materials generally have different response to the photons with different wavelength or polarizations, and in the generation of terahertz radiation by difference-frequency generation. 15,16 Up to now, spiral phase plate, hologram, q-plate and mode converter are the usual technology for the generation of optical angular momentum.…”