Ultra-compact and -broadband integrated plasmonic waveplates with high efficiency

Ultra-compact and -broadband integrated gold plasmonic half-wave and quarter-wave plates (HWP and QWP) based on the mode interference mechanism are proposed with applications in magneto-photonics, mode- and polarization-division multiplexing. The numerical simulations based on a finite element method reveals that the proposed HWP offers a maximum polarization conversion efficiency of 99.6% at a wavelength of lambda(0) = 1.55 mu m with a 1 dB bandwidth of 140 nm (lambda(0) = 1.47-1.61 mu m), covering 82% of the S to L telecommunication bands. In this wavelength range, HWP has an insertion loss below 2.3 dB and an extinction ratio between 9 and 24 dB, respectively. The presented QWP functions over the C telecommunication band (lambda(0) = 1.53-1.565 mu m), where the transmission contrast between its transverse magnetic and electric modes is 0 +/- 0.04. Moreover, QWP offers a polarization rotation angle in the range of 45 +/- 5 degrees over the same wavelength range. Finally, this paper illustrates that the proposed waveplates have a robust tolerance to fabrication errors.

Automated summary

This research presents ultra-compact and broadband integrated gold plasmonic half-wave and quarter-wave plates based on the mode interference mechanism. Numerical simulations demonstrate that the proposed waveplates have high polarization conversion efficiency and low insertion loss within specific wavelength ranges.