an optical switch including a light passageway having a changeable cross - sectional area , an activation light responsive piezoelectric element associated with the light passageway , the activation light responsive piezoelectric element being operative to change its shape in response to activation light impinging thereon and a conductive element operatively associated with the piezoelectric element for enhancing activation light responsiveness thereof , the activation light responsive piezoelectric element being associated with the light passageway and being operative such that changes in the shape of the piezoelectric element cause changes in the changeable cross - sectional area of the light passageway sufficient to govern the passage of light along the light passageway . logic gates and logic functionality employing an optical switch are also described .