metric Oscillator - Beckman Institute Laser Resource Center

Part 7: HeNe alignmentRequired materialsHeNe2 HeNe routing mirrors2 pinhole mounting apertures with UV paper mounts (provided in the accessoriesshipped with the MOPO-710)leveling device1. Set up a low energy alignment HeNe laser (0.5-2m'W). Use one fixed and onekinematic HeNe mirror to steer the beam into the MOPO-710,as shown in figure (3-8).2. Align the HeNe beam on the center of the visible dichroic mirror 2 (VDC2)3. Install pinholes pH1 and pH2 into the baseplate, at the locations shownin figure (3-9).4. Remove the high reflector (HR) of the resonator cavity of the power oscillator.5. Align the HeNe beam though pinholes pH1 and pH2 using the adjustments onVDCl and VDC2.6. Using a white card, check the position of the HeNe beam on both faces of theBBO crystal and the compensator block. Translate the BBO crystal and thecompensator horizontally to center the HeNe beam on both crystals.7. Verify that the HeNe beam is approximately centered on the OC, UVTM4 andUVTM5. Make sure that the HeNe beam is not clipped by any of the optics.8. Adjust the position of the output coupler (OC) of the power oscillator'sresonator cavity such that weak surface HeNe back reflections are collinear withthe original HeNe beam path.9. Install the high reflector (HR) optic and mount onto the baseplate.10. Adjust the position of the HR so that weak surface HeNe back reflections arecollinear with the original HeNe beam path. Secure all mounting screws on theHR mount.This completes the HeNe alignment of the system.