Displacement measurement system

US7545507B2 · kind B2 · utility

Assignee

• AGILENT TECHNOLOGIES, INC. · US

Inventors

• William Clay Schluchter · Los Altos, US
• Miao Zhu · San Jose, US
• Geraint Owen · Palo Alto, US
• Alan B. Ray · Palo Alto, US
• Carol Courville · San Jose, US

Key dates

• Filing date: Mar 15, 2007
• Grant date: Jun 9, 2009
• Expiry date: Jul 3, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70775
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A displacement measurement apparatus includes a light source, a splitter grating, a measurement grating, and first a second detector arrays. The splitter grating splits a light beam into first and second measurement channels that each illuminates the measurement grating. The first and second measurement channels split into 0th and 1st order diffraction products at the measurement grating in a first pass and recombine at the measurement grating in a second pass before being measured at the first and second detector arrays.