Rib waveguides for mid-infrared silicon photonics

Abstract

Design rules for both single-mode and polarization-independent strained silicon-on-insulator rib waveguides at the wavelength of 3.39 m are presented for the first time to our knowledge. Waveguide geometries with different parameters, such as waveguide height, rib width, etch depth, top oxide cover thickness and sidewall angle, have been studied in order to investigate and define design rules that will make devices suitable for mid-IR applications. Chebyshev bivariate interpolation with a standard deviation of less than 1% has been used to represent the zero-birefringence surface. Experimental results for the upper cladding stress level have been used to determine the influence of top oxide cover thickness and different levels of upper cladding stress on waveguide characteristics. Finally, the polarization-insensitive and single-mode locus is presented for different waveguide heights.

Low loss silicon waveguides for the mid-infrared

“…It was found the waveguide propagation losses were similar. This is not surprising taking into account the design and dimensions of the waveguides tested [16,19]; therefore, it can be assumed the polarisation dependence of the propagation loss is not significant for the previously described setup and device dimensions.…”

“…We have previously theoretically investigated MIR SOI rib waveguides [16], and in this paper we report, for the first time, experimental verification of low loss SOI waveguiding at a wavelength as long as 3.39 μm. As the 3-5 μm wavelength range is interesting due to several application areas, the results presented here could lead to the realisation of a range of MIR integrated photonic circuits on SOI platform.…”

“…We have designed SOI waveguides following the guidelines published in [16]. Rib waveguides with a height of 2 μm, width of 2 μm and etch depth of 1.2 μm were chosen, as their overall dimensions ensured efficient coupling from MIR optical fibres since a low power MIR laser was used in this work.…”

Nonlinear Group IV photonics based on silicon and germanium: from near-infrared to mid-infrared

“…Towards mid-IR applications, different types of Group IV waveguides have been reported recently, based on silicon-on-insulator (SOI) [191][192][193], silicon-on-sapphire [142,194,195], silicon-on-porous-silicon [192], siliconon-nitride [196,197], suspended membrane silicon [198], silicon pedestal [199], and germanium-on-silicon [200]. Most of the waveguides are not aimed specifically at nonlinear applications, and little attention has been paid to dispersion engineering [196].…”

Second-order nonlinear silicon-organic hybrid waveguides

“…The vision of creating mid-IR applications using the inexpensive siliconphotonics platform [8] has already led to a number of publications in the following topics: Silicon waveguides pumped below the two-photon absorption (TPA) edge with powers as high as 33.5 W (45 dBm) [9], low-loss propagation in the 2-6 µm wavelength range [10,11], light generation at 2.4 µm with standard telecom sources [12], high-Q SOI photonic crystal cavities at 4.4 µm [13], Raman amplification at 3.39 µm [14], and extensive simulations for single-mode operation and polarization-independent operation in SOI rib waveguides in the mid-IR region [15].…”