Accession Number : ADA188362

Title :   A Continued Study of Optical Sound Generation and Amplification

Descriptive Note : Annual rept. 1 Oct 1986-30 Sep 1987

Corporate Author : MISSISSIPPI UNIV UNIVERSITY PHYSICAL ACOUSTICS RESEARCH LAB

Personal Author(s) : Bass, Henry E ; Shields, F D

PDF Url : ADA188362

Report Date : 31 Oct 1987

Pagination or Media Count : 36

Abstract : During the past year, research has concentrated on optoacoustic generation in fluids, ultrasonic absorption in water/polymer mixtures, and sound propagation through a gas with a nonequilibrium distribution of internal energy states. Preliminary optoacoustic measurements in water and propanol demonstrate that the theory explains experimental results for these weakly absorbing fluids. Attention then shifted to a strongly absorbing fluid with relaxing internal energy states, CS2. Initial measurements in CS2 reflect a non-linearity of signal strength with increasing input energy and the formation of visible bubbles near the optical focal point. A theoretical model for the optoacoustic signal as a function of time in the linear regime (energies too low for bubble formation) has been developed. A new system to measure small absorption (approx. 1 db/m) in fluids in the frequency range 90 KHz to 1 MHz has been tested. Measurements in distilled water indicate that this system is capable of measuring attenuation as small as 0.05 dB/m.

Descriptors :   *ACOUSTIC ABSORPTION, *ACOUSTOOPTICS, *SOUND, *SOUND GENERATORS, ACOUSTICS, AMPLIFICATION, CARBON DISULFIDE, ENERGY, ENERGY TRANSFER, FLUIDS, INPUT, MIXTURES, NONLINEAR SYSTEMS, OPTICAL PROPERTIES, POLYMERS, PROPANOLS, SIGNALS, SOUND TRANSMISSION, STRENGTH(GENERAL), ULTRASONICS, VIBRATION, VISIBLE SPECTRA, WATER

Subject Categories : Acoustooptic and Optoacoustic Devices
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE