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Register a new userMode cooperation in two-dimensional plasmonic distributed-feedback laser
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Added by
Evgeny Andrianov Dr
Publication date
2017
fields
Physics
and research's language is
English
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Plasmonic distributed-feedback lasers based on a two-dimensional periodic array of metallic nanostructures are the main candidate for nanoscale sources of coherent electromagnetic field. Strong localization of the electromagnetic field and the large radiation surface are good opportunities for achieving an ultrashort response time to the external actions and creating beam directionality. At the same time, the investigation of such a system is a challenging problem. In this paper, we present an exhaustive study of the operation of a two-dimensional plasmonic distributed-feedback laser. We show that the complex structure of the modes of a periodic plasmonic array and the nonlinear interaction between the modes through the active medium lead to a new effect, namely, mode cooperation. Mode cooperation is manifested as the generation of the modes in an allowed band with a high threshold instead of modes localized near the band gap with a low threshold. Suppression of lasing of the modes at the edge of the band gap results in widening of the radiation pattern above the generation threshold. This paves the way for effective control and manipulation of the radiation pattern of nanoscale systems, which is of great importance for applications in spectroscopy and optoelectronics.
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Electrically-pumped lasers directly grown on silicon are key devices interfacing silicon microelectronics and photonics. We report here, for the first time, an electrically-pumped, room-temperature, continuous-wave (CW) and single-mode distributed feedback (DFB) laser array fabricated in InAs/GaAs quantum-dot (QD) gain material epitaxially grown on silicon. CW threshold currents as low as 12 mA and single-mode side mode suppression ratios (SMSRs) as high as 50 dB have been achieved from individual devices in the array. The laser array, compatible with state-of-the-art coarse wavelength division multiplexing (CWDM) systems, has a well-aligned channel spacing of 20 0.2 nm and exhibits a record wavelength coverage range of 100 nm, the full span of the O-band. These results indicate that, for the first time, the performance of lasers epitaxially grown on silicon is elevated to a point approaching real-world CWDM applications, demonstrating the great potential of this technology.
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We present a novel scheme of structured light laser with an astigmatic mode converter (AMC) as intracavity element, first enabling the generation of Hermite-Gaussian (HG) modes with fully controlled two-dimensional (2D) indices (m,n) and vortex beams carrying orbital angular momentum (OAM) directly from cavity. The 2D tunability was realized by controlling the off-axis displacements of both pump and intracavity AMC. The output HGm,n beam could be externally converted into OAM beam with 2D tunable radial and azimuthal indices (p,l). With the certain parameter control, vortex beam carrying OAM also could be directly generated from the cavity. Our setup provides a compact and concise structured light source. It has great potential in extending various applications of optical tweezers, communications, and nonlinearity.
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