Ultrahigh-Q photonic crystal nanobeam cavities with H-shaped holes

•A 1D photonic crystal nanobeam cavity with H-shaped holes was proposed.•Cavity optical performances have been studied by using the 3D FDTD method.•Cavity modes with ultrahigh Q and relatively small V have been observed.

A novel one-dimensional photonic crystal InGaAsP nanobeam cavity perforated by H-shaped holes is proposed in this paper. By using the three-dimensional finite-difference time-domain method, the performances of the proposed cavity in terms of quality factor (Q) and mode volume (V) are analyzed numerically. The results show that an ultrahigh Q   of ~6.6×107~6.6×107 together with a relatively small V   of ~0.59(λ/n)3~0.59(λ/n)3 can be achieved, leading to the figure of merit Q/VQ/V as high as ~1.1×108~1.1×108 per cubic wavelength in a material. This proposed H-shaped hole cavity not only will be very beneficial for low-threshold nanoscale lasers and low-power nonlinear devices, but could also serve as an excellent candidate of optomechanical crystals for routing and coupling optical and mechanical energies.

Graphical abstractA one-dimensional photonic crystal InGaAsP nanobeam cavity perforated by H-shaped holes is proposed. Cavity modes with ultrahigh Q and relatively small V have been observed.Figure optionsDownload full-size imageDownload as PowerPoint slide