Slab-edge modes in two-dimensional photonic crystals

Abstract

We demonstrate the existence of surface waves in two-dimensional photonic crystal slab edges. In finite-sized air-terminated photonic crystal boundaries, the slab-edge mode turns into a lasing mode under pulsed optical pumping conditions. Analyses of the modal behaviors of the slab-edge modes by means of calculations based on the plane wave expansion method and the finite-difference time-domain method show that resonant frequencies and quality factors are strongly dependent on the termination parameter and the shape of the slab corner.

High transmitting and coupling characteristics of light at the surface of a photonic crystal with a triangular lattice of air holes

“…The straight line denotes light line. The dispersion characteristics of the surface modes are strongly dependent on the truncated termination, and different surface structures give rise to different surface modes profiles [4,5,9]. One can see that the cutoff frequencies of all these surface modes on the side of air band of these surface modes shifts to lower frequencies with the increase of τ values.…”

“…For TE modes (electric fields are perpendicular to the axes of the air holes), the PBG opens for the normalized frequency a∕λ ranging from 0.258 to 0.365, where λ is the optical wavelength. A termination factor τ is introduced and defined as 2h∕ 3 p a (the same as [5] and [9]), where h is the distance from the center of the air holes of the outmost layer to a PhC edge, as shown in Fig. 1.…”

“…When PhCs are terminated appropriately, they can support surface modes, which lie in photonic band gaps (PBGs) and below the light line. Surface waves are EM waves propagating along the interface between PhCs and open space and decaying into both media [2][3][4][5][6][7][8][9][10], similar to surface plasmons on metallic surfaces [11]. It is believed that surface modes open up a new route for manipulation of EM waves at the surface of PhCs [12].…”

High-Q optical filter based on photonic crystal surface-mode microcavity

“…Photonic crystal (PhC) micro-cavities on silicon-on-insulator (SOI) structures can be utilized for such optical filters due to their strong confinement of light [3,4]. Among several designs of PhC micro-cavities, surface mode resonators in two-dimensional (2D) PhC slab are of importance as they can be easily side-coupled with silicon-wire waveguides [5][6][7].…”

Optical surface edge Bloch modes: low-loss subwavelength-scale two-dimensional light localization

“…An optical surface Bloch mode [1][2][3][4][5][6][7] is an optical state evanescently bound at a surface on a periodic structure, and the mode frequency is located within a photonic bandgap (PBG). Tamm [8] studied electronic surface Bloch modes.…”