In:
Optics Letters, Optica Publishing Group, Vol. 47, No. 5 ( 2022-03-01), p. 1037-
Abstract:
A tip nanofocusing light field, with high electric-field intensity and nanoscale mode volume, can significantly improve nonlinear light scattering efficiency, thereby greatly promoting the development of strong-field nano-optics. Here, tip-enhanced four-wave mixing (FWM) is theoretically analyzed through two ultrafast radial vector beams internally illuminating an Ag-coated silica tip (ACST). Two femtosecond pulses, with radial electric vectors and pulse width of 100 fs, are adopted as excitation sources to illuminate the ACST. Degenerate tip-enhanced FWM ( ω FWM = 2 ω 1 − ω 2 ) with a nonlinear conversion efficiency of ∼10 −5 is achieved. The peak electric-field amplitude of the two pump pulses is 5 × 10 7 V/m, which is two orders of magnitude lower than that of the external excitation method. Further theoretical analysis shows that the conversion efficiency of the tip-enhanced FWM has strict frequency detuning dependence characteristics, and is closely related to the frequency response of the tip nanofocusing light field. This plasmonic tip provides an approach for enhancing nonlinear nano-optics, and may be used in the field of tip-based FWM nanoscopy.
Type of Medium:
Online Resource
ISSN:
0146-9592
,
1539-4794
Language:
English
Publisher:
Optica Publishing Group
Publication Date:
2022
detail.hit.zdb_id:
243290-0
