Dual laser optical system and method for studying fluid flow

US4391518A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Robert B. Owen · Huntsville, US
• William K. Witherow · Huntsville, US

Key dates

• Filing date: Jan 12, 1981
• Grant date: Jul 5, 1983
• Expiry date: Jan 12, 2001

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N21/45
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A dual laser optical system and method is disclosed for visualization of phenomena in transparent substances which induce refractive index gradients such as fluid flow and pressure and temperature gradients in fluids and gases. According to the invention two images 68 and 70 representing mutually perpendicular components of refractive index gradients may be viewed simultaneously on screen 66. Two lasers 10 and 12 having wave lengths in the visible range but separated by about 1000 angstroms are utilized to provide beams 14 and 20 which are collimated into a beam 32 containing components of the different wave lengths. The collimated beam 32 is passed through a test volume 33 of the transparent substance. The collimated beam is then separated into components of the different wave lengths and focused on to a pair of knife edges arranged mutually perpendicular to produce and project images 68 and 70 onto screen 66.