High transmission and single-mode operation in low-index-contrast photonic crystal waveguide devices

Abstract

We investigate photonic crystal films made of low-index glass materials. Polarization-sensitive waveguiding and single-mode operation (with losses as low as 1.7 dB/mm) have been observed in wide multimode photonic crystal waveguides after propagation of some millimeters. Furthermore, single-mode operation and transmission as high as about 50% per bend has been observed experimentally in low-index photonic crystal waveguide bends

Glass nanofibers for micro- and nano-scale photonic devices

“…The measured bending loss of a 5-lm-radius bend assembled with a 550-nm-diameter glass nanofiber is typically less than 1 dB at 633-nm wavelength, which is small enough for microphotonic circuits. By comparison, bending waveguides based on planar photonic crystal structures not only require multiple periods (which increase the overall size) and sophisticated fabrication techniques [23][24][25], but they also have inevitable out-of-plane loss. In contrast, aerogel-supported nanofiber bends offer the advantages of compact overall size, low loss, simple structure and easy fabrication [26].…”

Waveguide bends from nanometric silica wires

“…Losses on the order of 1 dB per bend are small enough to be acceptable for many photonics devices. For comparison, waveguide bends formed with planar photonic crystal structures not only require multiple periods (which increase the overall size) and sophisticated fabrication techniques, but they also have inevitable out-of-plane loss [14][15][16] . In contrast, waveguide bends assembled with nanometric silica wires show the advantages of compact overall size, low optical loss, simple structure and easy fabrication 17 .…”

Scattering of plane waves by slabs of dielectric photonic crystal with line defects

“…Two-dimensional PCs, which are composed of rods arranged to a periodic lattice, and which show defects of various types have been used in a very wide frequency range for a large number of applications from integrated optics to powerful vacuum electron devices. In particular, defect modes have successfully been employed for filtering and coupling (e.g., [9,11,[15][16][17]), waveguiding and bending (e.g., [2,10,[18][19][20][21]), and splitting/combining (e.g., [12,[22][23][24]) of EM radiation. They have also been used as mirrors [7], resonant cavities [13,25,26], and fibers [14,27].…”

“…In some papers, field patterns of the defect modes have been calculated and analysed (see, e.g., [2,11,15,19,28]). Both structures, which are infinite in one direction and completely finite, have theoretically been studied with the aid of various methods like plane wave method, FDTD method, transfer matrix method, etc.…”

“…Two types of defects, i.e., line (e.g. [2,4,9,15,[21][22][23]]) and point (e.g., [3,5,8,20,28]) defects which appear in either the scheme 'rods in air as host medium' (e.g., [2,4,10,17,18]) or the scheme 'air holes in a homogeneous host medium'(e.g., [6,9,14,[19][20][21]), are usually considered. Most of the performed studies were devoted to PCs made of non-dispersive dielectric materials.…”