Browse Prior Art Database

Optical System for High Resolution Velocity And Displacement Maps

IP.com Disclosure Number: IPCOM000107202D
Original Publication Date: 1992-Jan-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 1 page(s) / 36K

Publishing Venue

IBM

Related People

Imaino, W: AUTHOR

Abstract

Described is a method for extending the focal range of a scanning laser Doppler vibrometer (LDV). This enables the use of smaller scanning spots and permits measurements with higher spatial resolution. Increased focal range is provided by the use of an autofocus system of the relay lens type, as shown in the figure. The focus actuator lenses move closer together or further apart depending on the signal from the focus detector, keeping the focused laser spot on the surface of the target. Also shown in the figure, the laser light impinging on the target consists of shifted and unshifted components such that both a heterodyne and homodyne signal are present at the photodetectors, permitting simultaneous measurements of displacement and velocity.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Optical System for High Resolution Velocity And Displacement Maps

      Described is a method for extending the focal range of a
scanning laser Doppler vibrometer (LDV).  This enables the use of
smaller scanning spots and permits measurements with higher spatial
resolution.  Increased focal range is provided by the use of an
autofocus system of the relay lens type, as shown in the figure.  The
focus actuator lenses move closer together or further apart depending
on the signal from the focus detector, keeping the focused laser spot
on the surface of the target.  Also shown in the figure, the laser
light impinging on the target consists of shifted and unshifted
components such that both a heterodyne and homodyne signal are
present at the photodetectors, permitting simultaneous measurements
of displacement and velocity.

      Disclosed anonymously.