Radiation-induced thermal noise in optoacoustic detection cells

Journal Article · Mon Oct 01 04:00:00 EDT 1984 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.334233· OSTI ID:6725560

Stewart, R B; Diebold, G J

When radiation is strongly absorbed in an optoacoustic detection cell, fluctuations in the radiation intensity give rise to thermal noise within the cell. The spectral density of the thermal noise thus generated is dependent on both the frequency response of the cell and the power spectral density of the radiation source. The frequency response function for the spectrophone cell is determined by application of elementary linear response theory to a solution of the heat equation for a uniformly heated cylinder. The power spectral density of coherent and incoherent radiation sources can be determined from their respective intensity autocorrelation functions. Radiation sources are discussed with regard to obtaining the smallest root-mean-square temperature fluctuations in the spectrophone cell. It is shown that optoacoustic noise is minimized by using a stabilized laser operating well above threshold. 15 references, 1 figure, 1 table.

• Research Organization: Brown Univ., Providence, RI
• DOE Contract Number: FG02-84ER13235
• OSTI ID: 6725560
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 56:7; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

440300* -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
CORRELATIONS
FLUCTUATIONS
FREQUENCY DEPENDENCE
FUNCTIONS
INFRARED SPECTROMETERS
LASERS
MEASURING INSTRUMENTS
NOISE
PHOTOACOUSTIC SPECTROMETERS
POWER DENSITY
RESPONSE FUNCTIONS
SPECTRAL FUNCTIONS
SPECTROMETERS
TEMPERATURE DEPENDENCE
VARIATIONS