A portable laser diode scanning head, aimable at each symbol to be read, emits and receives non-readily-visible laser light, and is equipped with a trigger-actuated aiming light arrangement for visually locating and tracking each symbol. A compact laser diode optical train and an optical folded path assembly, as well as an interchangeable component design and an integral window construction for the head also are disclosed. An embodiment that employs a stationary folding mirror mounted in fixed stationary relationship with a curved collecting mirror and a lightweight, movable scanning mirror is disclosed.