Lightwave propagation through a 120° sharply bent single-line-defect photonic crystal waveguide

Abstract

We have demonstrated 1.55 μm wavelength lightwave propagation through a 120° sharply bent waveguide formed in a triangular-lattice two-dimensional photonic crystal (2D PC). Such propagation has not previously been experimentally confirmed. The photonic crystal was fabricated in a silicon-on-insulator (SOI) wafer with the top silicon layer of the wafer used as a core layer. A 877-μm-long single-line-defect waveguide was formed in the PC with a sharp 120° bend near the middle of the waveguide. A tapered-hemispherical-end fiber was coupled to the input end of the waveguide for the light input, and the output from the other end of the waveguide was directly observed by scanning its near-field profile with another tapered-hemispherical-end fiber.

Designing finite-height two-dimensional photonic crystal waveguides

“…In particular, the high losses observed in Ref. 15 might be explained as a consequence of using a too short wavelength.…”

“…4,[6][7][8] For the case of two-dimensional photonic crystal slabs in air ͑finite height crystals͒, the existence of bound states has been demonstrated theoretically, 16,17 and experimental letters on crystal slabs have also appeared. 9,15,18 Naturally, planar waveguides based on photonic crystals cannot be of infinite height, and guidelines for the design of finite-height waveguides are, therefore, important for the realization of planar photonic crystal waveguides. In this letter, we compare calculations on two-dimensional photonic crystals with the dispersion relations for the media above and below the crystal slab.…”

“…In Ref. 15, measurements were carried out for this type of waveguide ͑substrate 2 below the slab and air above͒ using normalized frequencies ⌳/ Ͼ0.5, and high losses were observed. High losses are in agreement with the fact that frequencies ⌳/ Ͼ0.5 are above the air line ͑and certainly above the substrate2 line͒.…”

A high sensitivity pressure sensor based on two-dimensional photonic crystal

“…PhCs have many attractive characteristics such as photonic bandgap (PBG), localization effect, and refraction effect. By introducing point defect and/or line defect, PhC-based devices can be made [2], such as PhC-based waveguide [3][4][5], nanocavity [6][7][8], low threshold lasers [9][10][11][12], PhC-based filter [13][14][15], PhC fibers [16][17][18][19], optical sensors, and so on.…”

Dynamic Control of Defective Gap Mode Through Defect Location

“…For the photonic crystal, the DGM has promising applications in high-Q resonators [16][17][18][19][20][21] , beam splitters [22,23] , sharp bend waveguides [24][25][26][27][28] and coupling structures [29][30][31] , while for the fusion plasma, it plays an important role in confining energetic particles and thus generating fusion energy [32,33] . However, little attention has been given to the effect of defect location on the DGM characteristics, and the types of boundary conditions which act as local defects were rarely focused on.…”