Formation of quartic solitons and a localized continuum in silicon-based slot waveguides

Abstract

We explore the possibility of exciting the so-called quartic solitons in specially designed slot waveguides based on silicon and silica or silicon nanocrystals. This requires the excitation of the structure with quasi-transverse-magnetic polarized pulses-for which the Raman effect is absent-and at a specific infrared wavelength for which only the second- and fourth-order group velocity coefficients are nonvanishing. Pulses launched in these conditions will generate a spectrally localized continuum coming from the spectral interference of many quartic solitons. DOI: 10.1103/PhysRevA.87.02580

Generation of two-cycle pulses and octave-spanning frequency combs in a dispersion-flattened micro-resonator

“…For a broadband comb, it is beneficial to have most of the comb lines experience such low dispersion. In this sense, widely flattened low dispersion would be desirable for an octave-spanning comb, with small comb-line power variations over the comb bandwidth.In this Letter, we show by simulation that mode-locked frequency combs with a 20 dB power variation of comb lines over an octave-wide bandwidth can be generated in dispersion-flattened ring resonators based on silicon nitride (Si 3 N 4 ) strip/slot hybrid waveguides, which are associated with the formation of two-cycle cavity solitons.The strip/slot hybrid structure proposed in [17,18] has unique dispersion engineering capability for highindex-contrast waveguides and is applicable to various spectral ranges [23] and material platforms such as silicon [17,18,24,25], silicon nitride [26], and chalcogenides [27,28]. The flattened dispersion has been investigated in numerous nonlinear effects in a waveguide [18,[24][25][26][27].…”

“…The strip/slot hybrid structure proposed in [17,18] has unique dispersion engineering capability for highindex-contrast waveguides and is applicable to various spectral ranges [23] and material platforms such as silicon [17,18,24,25], silicon nitride [26], and chalcogenides [27,28]. The flattened dispersion has been investigated in numerous nonlinear effects in a waveguide [18,[24][25][26][27].…”

Analysis and design of fibers for pure-quartic solitons

“…Other theoretical efforts aimed to elucidate the behavior of NLS solitons in the presence of significant FOD [8][9][10][11][12][13][14]. Given the difficulty of engineering optical platforms with dominant FOD over a sufficiently large bandwidth, most of these predictions were never experimentally confirmed.…”

Nonlinear Group IV photonics based on silicon and germanium: from near-infrared to mid-infrared

“…Relative to many nonlinear materials such as SRO, SRN, chalcogenides, and polymers, silicon has a sufficiently large index to form a slot waveguide [47][48][49][50][51]. Moreover, adding a slot layer provides more design freedom to tailor chromatic dispersion, as reported in standard slot waveguides [51][52][53][54][55][56][57][58] and strip/ slot hybrid waveguides [59][60][61][62][63]. A high refractive index is also beneficial to build a slow light element with reduced group velocity of light, which can effectively increase optical length for nonlinear interactions and reduce power requirement [64][65][66].…”

“…This approach can produce a very flat dispersion profile over an ultrawide bandwidth, with dispersion flatness improved by 1-2 orders in terms of dispersion variation divided by lowdispersion bandwidth. More importantly, it is applicable to different material combinations and wavelength ranges [59][60][61][62][63].…”