1. Cavity length alignement 1.Two alignement mirrors -> symmetric beam image 2.PZT sweeping with an amplitude = several FSR 3.Shift two plane mirrors (in symmetric manner) until

2. Basics of Gaussian beams matching Design constraints: -enough place between lens and cavity waist (alignment mirrors + cavity) -lenses availability Desirability: -alignment independence for the two beam parameters (waist, position) a. s/f=1 : waist=const, position-linear b. s – max of magnification: waist-linear, position-const

3. Waist variation vs lens (f=500mm) position Cavity mode: - radius – 1.5mm - Rayleigh range – 6850mm Beam parameters after the lens (f=500mm) - radius – 0.1mm - Rayleigh range – 30mm Coupling errors: - position - waist may be used to controle of mode matching

4. Astigmatic beam matching. 1. Two general astigmatic beams : very complicate optical scheme -> losses, alignnement, beam parameters measurement 2. Two sipmle astigmatic beams: two orthogonal sets of the cylindrical lenses -> beam parameters measurement lenses selection (design constraints)