Fast fiber-laser alignment: beam spot-size method

A novel fast and cost-effective method is introduced for the active alignment of a fiber to a laser diode: only four easy laser beam spot-size measurements are required for moving the fiber tip from the far field to the proximity of the optimal alignment position, thus dramatically reducing the total alignment time (at least five times faster than a conventional method), as experimentally confirmed. Moreover, in contrast to the existing methods, the new method is failure-proof. The principle of the proposed method can be applied generally to any type of packages and is illustrated by an example of a butterfly package.