Temperature dependence of the thermo-optic coefficient of InP, GaAs, and SiC from room temperature to 600 K at the wavelength of 1.5 μm

Abstract

The thermo-optic coefficient ∂n/∂T has been measured from room temperature to 600 K at the wavelength of 1523 nm in three important semiconductors for fiber-optic device fabrication, namely, InP, GaAs, and 6H–SiC. The adopted technique is very simple and is based on the observation of the periodicity of the signal transmitted, at the desired wavelength, by an étalon made of the material under test, when it experiences a temperature variation. The values of ∂n/∂T measured in InP and GaAs at room temperature are in agreement with previously reported ones, but increase with temperature with a weak quadratic dependence. SiC conversely shows a lower thermo-optic coefficient (2.77×10−5 K−1) at 300 K, which, however, doubles for a 300 K temperature increase.

Wavelength-sized GaAs optomechanical resonators with gigahertz frequency

“…2͑f͔͒ is ⌬T =n eff / ͑dn/ dT͒ ϫ ͑⌬ / 0 ͒, where dn/ dT= 2.35ϫ 10 −4 K −1 in GaAs at room temperature. 19 In extreme cases, the resonance shift reaches 100 nm corresponding to a temperature increase ⌬T Ͼ 700 K at which the disk is irreversibly damaged after desorption of As atoms from the GaAs surface. 20 Note that heating can also induce optical resonance shift by means of direct thermal expansion of the disk gallery, in proportion of ␣ L = 6.05ϫ 10 −6 K −1 , the room temperature thermal expansion coefficient.…”

Compact Integration of Optical Sources and Detectors on SOI for Optical Interconnects Fabricated in a 200 mm CMOS Pilot Line

“…Most likely this is because when the ambient temperature is changed, it affects both the silicon waveguide and the InP-based microdisk cavity, while the self heating effect in CW mode only heats up the disk cavity. As the thermo-optic coefficients for these materials are similar [22], [23], the phase difference between the output from the microdisk and the reflected light from the fiber coupler remains more or less constant and hence no oscillations are observed.…”

Temperature stabilization of optofluidic photonic crystal cavities

“…For a PhC waveguide whose air holes have been infiltrated with another material, the effective refractive index experienced by a particular guided mode depends on the combination of the two refractive indices ͑PhC substrate material and infiltrated material͒, weighted by the filling fraction the relative electric field overlap with the corresponding material. Given that the thermo-optic coefficient for most common PhC substrate materials ͑Si, III-V semiconductors, etc.͒ is positive, 17 while it is negative for most liquids 18 and polymers, 19 there is a large range of material combinations for which the effective index of the combination may be rendered temperature insensitive if the guided mode has an appropriate portion of electric field overlap in each material. We now express this concept mathematically by considering the field distribution in a resonant fluid-infiltrated PhC cavity.…”