It is shown herein that submicron-scale displacement can be measured with a simple optical arrangement which contains a laser diode, two mirrors and a basic webcam. The coefficients of thermal expansion (CTE) of steel and copper alloy rods have been measured with this system. The CTE results were obtained by measuring the length change with respect to the temperature. The average CTE measurement was 12.25 +/- 0.10 x 10(-6)/K for the steel, and 18.35 +/- 0.25 x 10(-6)/K for the copper alloy. As a result, it is evident that the proposed system can be used for industrial projects and applications, as well as undergraduate or graduate level laboratory experiments which require precise measurements.