Browse Prior Art Database

Acoustic Monitoring Device for Temporal And/Or Spatial Characterization of Pulsed or Modulated Energetic Beams

IP.com Disclosure Number: IPCOM000047463D
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Coufal, H: AUTHOR [+2]

Abstract

A device is described which utilizes photoacoustic effects to monitor beam characteristics, such as the power of the incident beam or the temporal or spatial profile of the incident beam. The device comprises a beam absorber with one or several thin film piezoelectric transducers attached to it at suitable locations. Acoustic reverberation is suppressed by using suitable sound-absorbing materials in contact with the beam absorber-transducer assembly. As a specific example, the device comprises a black ceramic plate 1 as the absorbing medium for monitoring a pulsed light beam 2 of 10-nanosecond duration. Three thin film transducers 3 are attached to three surfaces, as shown in Fig. 1. The incident light beam from a nitrogen laser, for example, has a cross-section of an elongated ellipse.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 89% of the total text.

Page 1 of 2

Acoustic Monitoring Device for Temporal And/Or Spatial Characterization of Pulsed or Modulated Energetic Beams

A device is described which utilizes photoacoustic effects to monitor beam characteristics, such as the power of the incident beam or the temporal or spatial profile of the incident beam. The device comprises a beam absorber with one or several thin film piezoelectric transducers attached to it at suitable locations. Acoustic reverberation is suppressed by using suitable sound-absorbing materials in contact with the beam absorber-transducer assembly. As a specific example, the device comprises a black ceramic plate 1 as the absorbing medium for monitoring a pulsed light beam 2 of 10-nanosecond duration. Three thin film transducers 3 are attached to three surfaces, as shown in Fig. 1. The incident light beam from a nitrogen laser, for example, has a cross-section of an elongated ellipse. The observed transducer signals are shown in Figs. 2 to 4. Figs. 2 and 3 correspond to the x and y projections of the beam. The elongated cross-section is manifested as a large and sharp y signal (Fig. 3) and a small and broad x signal (Fig. 2). Due to the fact that the material used as the absorber has an extremely large absorption coefficient, the incident light beam penetrates only about 0.1 micron into the sample. The z signal (Fig. 4) therefore shows the temporal profile of the incident beam. Depending on the requirements, the device described can be used as a fast p...