He-Ne Laser

Diode Laser

Wave length, λ [nm]

633

532

Focal length of focusing lens, f [mm]

400

400

Beam diameter at e-2 intensity [mm]

1.35

1.35

Beam spacing, s [mm]

38.87

39.13

Calculated half-angle of beam intersection, θ

2.78˚

2.8˚

Fringe spacing, δ_f [μm]

6.53

5.45

Velocimeter transfer constant, K [MHz/m·s⁻¹]

0.153

0.183