1. Walking the Beam §Often a laser can work but the beam is not parallel to the bore. §This results in serious losses and low output power. §If left unchecked this will drastically shorten the tube life.

2. Rotate one Mirror slightly §Monitor the output power or the beam current. §Let the output reduce by around 20%

3. Rotate the other mirror in the same direction §Regain the power by rotating the opposite mirror. §Seek a local maximum.

4. Repeat until maximum power is obtained §Rotate the first mirror again. §An overall maximum will eventually be reached.

5. Tuning §Tuning is similar to walking. §Only one mirror is rotated to seek a local maximum. §The other mirror is left untouched.

6. Other Applications §Walking is also used to launch optical fibres and align complex systems like the multi- photon and UV confocals.