RESUMO
We investigate electrically pumped, distributed feedback (DFB) lasers, based on gap-plasmon mode metallic waveguides. The waveguides have nano-scale widths below the diffraction limit and incorporate vertical groove Bragg gratings. These metallic Bragg gratings provide a broad bandwidth stop band (~500 nm) with grating coupling coefficients of over 5000/cm. A strong suppression of spontaneous emission occurs in these Bragg grating cavities, over the stop band frequencies. This strong suppression manifests itself in our experimental results as a near absence of spontaneous emission and significantly reduced lasing thresholds when compared to similar length Fabry-Pérot waveguide cavities. Furthermore, the reduced threshold pumping requirements permits us to show strong line narrowing and super linear light current curves for these plasmon mode devices even at room temperature.
RESUMO
We demonstrate lasing in Metal-Insulator-Metal (MIM) waveguides filled with electrically pumped semiconductor cores, with core width dimensions below the diffraction limit. Furthermore these waveguides propagate a transverse magnetic (TM0) or so called gap plasmon mode [1-4]. Hence we show that losses in sub-wavelength MIM waveguides can be overcome to create small plasmon mode lasers at wavelengths near 1500 nm. We also give results showing room temperature lasing in MIM waveguides, with approximately 310 nm wide semiconductor cores which propagate a transverse electric mode.