Low-power, high-performance, and small-footprint, single-pump optical parametric amplifier for photonic integrated circuits

Abstract

A single-pump optical parametric amplifier (OPA) is modeled using a p-toluene sulfonate (PTS) filled silicon-based slotted photonic crystal waveguide (SPCW). The PTS-SPCW has CMOS-process compatibility and offers slow-light enhanced nonlinearity of PTS due to extreme optical confinement in SPCW. The adverse effects of two-photon absorption and free carrier absorption are absent in PTS in the standard optical communication window. The coupled nonlinear Schrödinger’s equations have been modified to analyze the OPA under slow-light propagation. Performances of the OPA are evaluated in both the high- and low- dispersive zones of the structure. The high dispersive zone exhibits high group indices to the operating waves, leading to a high parametric gain (≈31 dB) and high conversion efficiency (≈27 dB) utilizing a 350 μm long PTS-SPCW and a pump power of 65 mW. However, this zone degrades the shape of a ≤10 ps pulse due to self-phase and cross-phase modulation. On the other hand, in the low dispersive zone, a similar parametric gain and conversion efficiency (both ≈29 dB) are attained utilizing a 1250 μm long PTS-SPCW and a pump power of 150 mW. Nevertheless, this zone degrades a 5 ps pulse only after a distance of 1500 μm. The analyses show a 30 nm bandwidth considering a gain above 30 dB. Investigation of the effect of fabrication imperfections shows excellent performance sustainability of the OPA up to a random error of 40 nm. These remarkable performances make this low-powered, small-footprint OPA suitable for achieving tunable optical amplification in photonic integrated circuits.