A technique for coupling the output of a laser diode (30) to an optical fiber (32) entails disposing an optical train (37,38) between the source and the fiber, and locating the fiber end at or near the exit pupil of the optical train. In one embodiment of the invention, light from the laser diode source is imaged by a first lens (37) of focal length f.sub.1, forming a magnified real image of the source at a convenient distance, the real image is reimaged by a second lens (37) of focal length f.sub.2, and the fiber end is located at the exit pupil. The real image may be reimaged approximately at infinity.