Ti:Sapph Laser

Equipment

Diode data sheet:

Water blocks: File:Waterblock.pdf

Crystal base: File:9081g.pdf

Cavity Geometry

Short arm length = 15 cm

Long arm length = 80 cm

Focusing region = 10.45 cm

Crystal is 5.1 cm from 7.5 cm ROC mirror

Folding angle is 18 deg

Will see if it's possible to move the short arm in and decrease the folding angle (both of these help the astigmatism). Geometric constraints of the mirror mounts prevent the original fully optimized version.

Alignment Procedure

1. Set up the HeNe so that it intersects some point at the cavity folding angle (relative to a line of holes on the table). At that point, place the center of the first curved mirror.
2. Angle the first curved mirror so that the beam travels straight along the hole line.
3. Place an iris along the HeNe path after the second HeNe mirror but before where cavity flat mirror will be set up. Make sure the beam passes through the iris when almost closed.
4. Place the crystal so that the beam travels into the crystal at the Brewster angle (this will require a tilt of 30.4 deg relative to the hole line), and therefore exits parallel to the hole line but slightly displaced. Make sure to get the distance from the center of the crystal to the mirror correct!
5. Place the center of the second curved mirror at the correct distance away from the crystal, on the displaced-but-still-parallel beam path.
6. Angle the second curved mirror so that it propagates away at the cavity folding angle, now on the other side of the hole line.
7. Place the output coupler at the desired distance for the long arm. Use the iris from step 2 to make sure it retroreflects the beam precisely.
8. Place the flat mirror at the short arm distance from the first curved mirror. Use the iris to align the retroreflection from the back of the mirror.

Things to Try

Remove short arm flat mirror and align blue along hene/780

Mode match 780 and look for interference at the output