Ab initio investigation of lasing thresholds in photonic molecules

Abstract

We investigate lasing thresholds in a representative photonic molecule composed of two coupled active cylinders of slightly different radii. Specifically, we use the recently formulated steady-state ab initio laser theory (SALT) to assess the effect of the underlying gain transition on lasing frequencies and thresholds. We find that the order in which modes lase can be modified by choosing suitable combinations of the gain center frequency and linewidth, a result that cannot be obtained using the conventional approach of quasi-bound modes. The impact of the gain transition center on the lasing frequencies, the frequency pulling effect, is also quantified.

Steady-stateab initiolaser theory for fully or nearly degenerate cavity modes

“…Among other advances, this new framework has shed light on weakly-scattering random lasers [24], on pump-induced exceptional points [11,12,25,26] and on coherent perfect absorption [27,28] and has opened up new ways of controlling the emission patterns of random as well as of microcavity lasers [29,30]. One of the major drawbacks of SALT is that its conventional formulation fails for the simulation of microlasers with nearly degenerate modes as occurring, e.g., in whispering gallery mode resonators with an inherent symmetry [2,6,8,10,12,31].…”

Dressed Linewidth Enhancement Factors in Small Semiconductor Lasers

“…As shown in (21) and Fig. 2(b), this effect is a phase rotation in the complex χ plane of the susceptibility.…”

“…Our approach is based on a frequency-domain formulation aimed at the fieldsource response of cavity modes in active nanophotonic devices [20]. Similar topics were also studied in the presence of active regions and open cavities [21]- [24]. We show that effects of small cavities (covering waveguide lasers [13]) on the lasing linewidth can be addressed with one complex parameter.…”

Analysis on the LSP and shell modes of a silver-strip plasmonic nanolaser

“…Assuming the lasing-mode frequency to be real-valued and following [3][4][5][6][7][8][9], we formulate the lasing eigenvalue problem (LEP) in terms of pairs of real positive numbers (λ s , γ s ), where λ s is the wavelength and γ s is the associated threshold value of material gain in the cylinder, introduced as imaginary part of the bulk refractive index. Note that the other LEP-like formulations exist and can be found in [10][11][12][13].…”