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To get information about the product stabilization within the photosynthetic electron transport chain, it is of interest to measure the heat evolved in the system upon irradiation. The cyanobacterium Synechococcus sp, containing both photosystems PS-i and PS-II, was chosen as the subject of investigation. LIOAS-measurements were performed a) in vivo with intact cells and b) in vitro with isolated PS-II and PS-I particles. In all cases the internal reference for maximal heat production [1] was the same system with inhibited photosynthetic activity. Compared to the conventional photoacoustic spectroscopy (PAS), LIOAS has a better time resolution (< 2 μs) and excludes contributions from modulated photosynthetic oxygen-evolution.

Optoacoustic spectroscopy is a potentially powerful tool for the determination of trace and ultratrace components of biochemical interest. We derive here an abbreviated theory of pulsed optoacoustic spectroscopy, describe the experimental apparatus, and report on the performance in the determination of NADH. Results are consistent with theory over the concentration range 1 × 10 −5 to 5 × 10 −7 , m . A projected lower limit for detection is 1 × 10 −8 , m . Possible applications to the study of nucleotide interactions are discussed.

Optoacoustic spectroscopy investigate solid, semi conductor and liquid samples which are strongly or weakly absorbing, or which preclude the use of reflectance or transmission spectroscopy due to scattering of the incident radiation. The material presented in this chapter demonstrates the great potentiality of OAS of condensed media.

The pump offset frequencies of CH 3 OH and CH 2 F 2 far-infrared(FIR) lasants with respect to the line center of CO 2 laser have been measured by means of Doppler-free optoacoustic spectroscopy.

There are two main OA methods to detect absorbed energy in condensed media: direct and indirect detection of acoustic vibrations. In the first case the acoustic vibrations are detected directly in the sample under study, an acoustic pickup is linked up with it. The main characteristics of this measuring technique are considered in Sects.3.1,2. In the second case the acoustic vibrations are detected in the gas or liquid contacting with the sample. As a rule, the introduction of an additional (‘immersion’) medium between the sample and the pickup improves their acoustic matching; it also facilitates the study of surface absorption in solids. Analysis of the indirect measuring method and a comparison with the direct one are given in Sects.3.3–5.

Photoacoustic spectroscopy (PAS, also called optoacoustic spectroscopy) although over 100 years old, has experienced renewed interest with the detection of trace levels of atmospheric pollutants. More recently PAS of condensed systems has resulted from a better understanding of the underlying physics of the PA effect. In this communication, I wish to illustrate the use of PAS to obtain the absorption spectra of soil and clay mineral solids, which are especially difficult to study by more conventional transmission or reflectance spectroscopy due to sample heterogeniety and light scattering artifacts.

Optoacoustic (OA) detection apparatus can be used for analysis of various optical absorbers in very dilute concentrations. Parameters of pulse OA spectroscopy as applied to highly transparent samples are derived allowing to compare the potentialities to these of conventional absorption methods. We consider a frequently used OA device based upon linear thermoelastic OA conversion. Practice of both amplitude and dynamic versions of OA method are discussed. The role of pure solvent contribution is revealed. Useful estimates are provided.

Laser-induced optoacoustic spectroscopy (LIOAS) was applied to the study of 13-cis (13RT), 11-cis (11RT), and all-trans (trRT)-retinal photoisomerization in various n-alkanes. From the analysis of ...

An analysis is made of the suppression of fluctuations of an acoustic signal and of reduction of the intrinsic relaxation times in stochastic excitation of a Raman-active transition.

Molecular spectroscopists have studied the absorption of optical radiation for over 100 years, but only in the last five years have experiments come forth on the subsequent relaxation of the molecular excitation to produce heat. By detecting this heat as an acoustic pulse using sensitive microphones and bolometers, the eventual fate of absorbed photons can be followed, both energetically and kinetically. Several examples of the unique information derived from this acoustic method of molecular spectroscopy will be presented.

A method and apparatus that significantly increases the sensitivity and flexibility of laser optoacoustic spectroscopy, with reduced size. With the method, it no longer is necessary to limit the use of laser optoacoustic spectroscopy to species whose absorption must match available laser radiation. Instead, "doping" with a relatively small amount of an optically absorbing gas yields optoacoustic signatures of nonabsorbing materials (gases, liquids, solids, and aerosols), thus significantly increasing the sensitivity and flexibility of optoacoustic spectroscopy. Several applications of this method are demonstated and/or suggested.

(1986). Laser Optoacoustic Spectroscopy. Optica Acta: International Journal of Optics: Vol. 33, No. 11, pp. 1338-1338.