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Core Sensor Platform

Optoacoustics’ core platform is built on an optical sensor that can measure changes in light intensity reflected from a tiny membrane embedded at its center.

These changes occur when acoustic waves collide with the membrane and cause it to vibrate. Our platform passively detects membrane displacement at sub-angstrom resolutions, so even minute changes can be detected and measured very precisely using optics and simple electronic processing. The result is a true-to-source signal that can be amplified or analyzed further without any loss of quality.

 

Sensing Path

The sensing path begins with light produced by a LED which travels over an optical fiber to the optical head, and is beamed onto the ultra-sensitive membrane. When the membrane vibrates, the intensity of the light it reflects changes, providing a basis for dynamic measurement. Reflected light travels over a second optical fiber to a photo detector, which produces the intensity-modulated data for signal processing.

Optoacoustics’ core platform contains no electronic components — the processing is performed in a subsystem that can reside at an ideal distance from the sensor. Using optical fiber for transmission ensures that membrane modulation data is not compromised, even at distances of over a kilometer.

 

Sensing Characteristics

Device sensitivity is determined by the intensity of light reflected off the vibrating membrane, and is controlled by two factors: the angle of the two optical fibers, and the distance from the membrane to the optical head. As the membrane moves away from the optical head, a greater amount of reflected light is collected by the second fiber. The amount of transferred light can increase until it reaches its maximum in terms of the optical fiber geometry. After this maximum light intensity is reached, a further increase in distance between the membrane and the optical head will result in a gradual decrease in the amount of reflected light collected.

Sensitivity calculations take each of these factors into account - along with the sensing application environment - to arrive at the optimum geometric arrangement and power levels.

 

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