A variable optical delay line using MEMS devices. A reflector on a micro machine linear rack is positioned and spaced from an input source and/or an output to receive and reflect input light waves toward the output. The distance between the reflector and the input and output is variable and thereby enables selective path delay compensation of the input light wave signals. Other disclosed embodiments utilize pivoting MEMS mirrors and selective adjustment of the mirror pivot angles to provide the selective path delay compensation required in a light wave system.