By conducting research on athermal silicon waveguides, viable CMOS compatible optoelectronic and photonic devices can be developed as temperature changes no longer affect the device performance. In such applications, appropriate waveguide dimensions, as well as materials with specific properties are required. Recently it was demonstrated that the subwavelength grating (SWG) effect gives an extra degree of freedom in the design of photonic circuits. The effective refractive index, in that case, is engineered through the use of waveguide core segments of different dielectric materials.;Here, we investigate athermal subwavelength grating waveguides. SWG structures with periodicities smaller than half the wavelength of light in the medium do not exhibit diffraction, reduces scattering, and can instead act as regular photonic waveguides of homogeneous effective core medium. Here we demonstrate both numerically and experimentally that by combining two materials with opposite thermo-optic coefficients, temperature independent behavior can be achieved.
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