PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 7071995

Microwatt ultrasonic power determination using laser interferometry.

R Reibold
View original source ↗Export metadata ↓

Abstract

A system using a water-immersed balance with laser interferometer for radiation force measurements has been developed which is capable of determining powers in the range of a few microwatts up to about 100 mW. High consistency of measuring values and low background noise levels are achieved by compensating thermal and atmospheric pressure drifts, shielding the balance system from convection currents and effective isolation from building vibrations. The sensitivity ascertained is 104 micrometer/mW or, expressed as interferometer steps (IS), 8740 IS/mW. The standard deviation for a power output of 100 mu W is less than 1% ; it increases to 11% for 3.5 mu W, the lowest value measured.

Explore related subjects

InterferometryLasersPhysical PhenomenaPhysicsUltrasonicsJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R Reibold. 1982. Microwatt ultrasonic power determination using laser interferometry.. https://doi.org/10.1016/0301-5629(82)90098-9

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2005

Dissipative solitons driving and bound state control via parameter gradients.

The effect of phase and intensity gradients on the motion of dissipative solitons in a nonlinear interferometer is investigated. We show how the forces exerted by parameter gradients on the solitons alter their interactions. Consequently, it is possible to tune the spectrum of soliton bound states via the introduction of proper spatial distribution of the system parameters. Furthermore, we show how the use of properly shaped parameter distributions can lead to a relevant reduction of the cross-talk between close by solitons in applications.

Interferometry↗
PubMed2003

Realization of a multichannel integrated Young interferometer chemical sensor.

We report on the design, realization, and characterization of a four-channel integrated optical Young interferometer device that enables simultaneous and independent monitoring of three binding processes. The generated interference pattern is recorded by a CCD camera and analyzed with a fast-Fourier-transform algorithm. We present a thorough theoretical analysis of such a device. The realized device is tested by monitoring glucose solutions that induce well defined phase changes between output channels. The simultaneous measurement of three different glucose concentrations shows the multipurpose feature of such devices. The observed errors, caused by the mismatching of spatial frequencies of individual interference patterns with those determined from the CCD camera, are reduced with different reduction schemes. The phase resolution for different pairs of channels was approximately 1 x 10(-4) fringes, which corresponds to a refractive-index resolution of approximately 8.5 x 10(-8). The measured sensitivity coefficient of the phase change versus refractive-index change of approximately 1.22 x 10(3) x 2pi agrees well with the calculated coefficient of approximately 1.20 x 10(3) x 2pi.

Interferometry↗
PubMed2003

Observing bacterial activity interferometrically.

It is shown that bacterial activity, even of slowly growing species, can be detected by precise interferometric measurements of refractive index changes of the culture medium. The bacteria-containing sample is kept in an isothermal block together with a reference liquid without bacteria. The biological activity is obtained from the difference of the index changes of these samples. Experiments were performed with Bacilo Calmette-Guérin. The order of magnitude of the observed total refractive index change was compatible with theoretical estimates based on the amount of available oxygen. An unexpected positive index change during the lag phase was observed, which might permit fast diagnostics in medical applications. This technique may provide cheap and quick tests of bacterial susceptibility with respect to antibiotics.

Interferometry↗