Enhanced sensitivity vibrometer

US8072609B1 · kind B1 · utility

Assignee

• The United States of America as represented by the Secretary of the Army · US

Inventors

• Sudhir Trivedi · Nottingham, US
• Venkataraman Swaminathan · Macungie, US
• Chen-Chia Wang · Newark, US

Key dates

• Filing date: Dec 30, 2008
• Grant date: Dec 6, 2011
• Expiry date: May 13, 2029

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/266
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An enhanced sensitivity laser vibrometer with increased output signal strength and more sensitive surface vibration detection, is provided by using a reflective mirror assembly to repeatedly bounce the sensing laser beam against the acoustic pressure-sensing diaphragm to magnify the acoustic incident pressure wave being detected. The enhancement in signal strength, in terms of power spectral density, is a function of the number of bounces squared and the detection of surface vibrations with a displacement of smaller than 4 picometers is demonstrated experimentally.