Deviation angle self compensating substantially achromatic retarder

US7450231B2 · kind B2 · utility

Assignee

• J.A. WOOLLAM CO., INC. · US

Inventors

• Blaine D. Johs · Lincoln, US
• Steven E. Green · Lincoln, US
• Craig M. Herzinger · Lincoln, US
• Duane E. Meyer · Lincoln, US

Key dates

• Filing date: Dec 4, 2006
• Grant date: Nov 11, 2008
• Expiry date: Apr 3, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/213
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A substantially achromatic multiple element compensator system for use in wide spectral range (for example, 190-1700 nm) rotating compensator spectroscopic ellipsometer and/or polarimeter systems. Multiple total internal reflections enter retardance into an entered beam of electromagnetic radiation, and the elements are oriented to minimize changes in the net retardance vs. the input beam angle resulting from changes in the position and/or rotation of the system of elements.