Technologies are generally described for fabricating a wafer level optical device using a plurality of substrates made of materials with a substantially compatible (e.g., same or similar) thermal expansion coefficient. An example device may include a first substrate including light-receiving or light-emitting elements, and a second substrate including optical elements located within through-holes of the second substrate. The through-holes can be configured to substantially align each of the light-receiving or light-emitting elements with a corresponding one of the optical elements. A thermal expansion coefficient of the second substrate can be configured to be substantially the same to a thermal expansion coefficient of the first substrate.