Static attitude measurement system for head suspension assemblies

A method for measuring the static attitude of a head suspension target while reducing measurement errors due to stray spots and internal reflections, the method comprising the steps of:

• providing a light beam;
• directing, by a beamsplitter, the beam onto a target from which a reflected beam is returned;
• collimating the beam directed onto the target;
• placing a collection optic between the beamsplitter and the target;
• producing a predetermined polarization state in the reflected beam by passing the beam and the reflected beam through a first polarization component;
• and
• detecting the reflected beam at the predetermined polarization state.

In a combined static attitude and Z-height measurement device for measuring the static attitude and Z-height of a head suspension target, the device including a light source for producing a light beam, a first beam splitter for producing first and second portions of the light beam, a second beam splitter for directing the first portion of the light beam toward the target from which a static attitude reflected beam is returned, a first detector for detecting light at substantially only a predetermined polarization state with the detector positioned to intercept the static attitude reflected beam, at least one directional component for directing the second portion of the light beam toward the target from which a Z-height reflected beam is returned and a second detector positioned to intercept and detect the Z-height reflected beam, the improvement comprising:

• a collection optic positioned between the second beam splitter and the target;
• a first quarter-wave plate positioned between the second beam splitter and the target for producing the predetermined polarization state in the static attitude reflected beam;
• and
• a second quarter-wave plate positioned before the target for producing a desired polarization state in the second portion of the light beam before it encounters the target.