Modulation bandwidth and energy efficiency of metallic cavity semiconductor nanolasers with inclusion of noise effects

Modulation bandwidth and energy efficiency of metallic cavity nanolasers are studied in both small signal and digital modulation formats. Special emphasis is placed on the effects of noise on data rate and energy efficiency. It is found that the data rate for nanolasers of small sizes is severely limited by noise-induced bit-error rate. The trade-off between size-reduction and noise effects leads to an optimal cavity size to achieve the highest data rate. The energy data-rate ratio decreases in general with device size, but starts to increase in ultrasmall devices, due to increased threshold current and noise effects. However, relatively high modulation rate and energy efficiency can be achieved in metallic cavity nanolasers. Calculations show that a low energy consumption of 30 fJ/bit at a high data rate of 120 Gbit/s can be realized in nanolasers as small as V = 16 (λ/n_r)³ (V is the laser cavity volume). Ultralow energy consumption per bit (<10 fJ/bit) does require smaller devices (V<2.1 (λ/n_r)³), while the noise limits the data rate to below 50 Gbit/s. Such a balanced and holistic consideration between device size, data rate, noise effects, and energy efficiency offers new perspectives to nanolaser design strategy for future onchip integrated nanophotonics systems.