Researchers from the National Institute of Standards and Technology (NIST) have developed a new type of accelerator that relies on lasers instead of mechanical strain to generate interference.
In its most basic sense, an accelerator is a sensor that measures proper acceleration – or the degree of change in body speed relative to its immediate frame of rest. It is used in cars, especially in the use of airbags once the driver suddenly steps on the brakes, creating a sudden change in speed. From modern smartphones to navigation systems used in missiles and aircraft, accelerators have helped objects detect the position and movement of objects.
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LAS VEGAS, NV – JANUARY 03: Pierre-Francois Tissot wears an In & Motion smart motorcycle bike vest at a press event for CES 2017 at the Mandalay Bay Convention Center on January 3, 2017 in Las Vegas, Nevada. The vest acts as a personal airbag by monitoring the rider and if he senses it will fall automatically.
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Creating Laser-Based Accelerometers
Although an accelerometer design has been established based on light, instead of the conventional mechanical weight, the new NIST design allows for a direct measurement process, leading to more accurate readings. Just about a millimeter thick, the optomechanical accelerator can operate at a wider frequency range and has been rigorously tested as part of determining its activity.
Furthermore, because it no longer relies on mechanical inputs – usually pressing on a piezoelectric surface – it no longer requires a time-consuming process for periodic calibration. Active acceleration accelerators use materials that are in contact with each other and decay over time. With lasers at a specific frequency as the sensory input for the new NIST accelerometers, it even opens up the potential of this optomechanical accelerator as a reference standard in capitalizing currently available conventional accelerators. .
In terms of navigation systems, its better error could mean better inertial sensitivity and navigation in systems that are particularly critical – submarines, missiles, satellites, military aircraft and more. Internal position sensing is especially important in cases where global positioning system (GPS) signals are not available.
Details on the design and testing of the optomechanical accelerator, led by Jason Gorman, Thomas Lebrun, David Long, and the other NIST researchers in an article entitled “Thermomechanically limited Broadband with optomechanical accelerator,” a was published in the journal Optica.
The newly developed sensor is part of the institute’s NIST program on Chip (NOAC), which aims to “bring world-class measurement science technology from the lab to users anywhere and at any time. “
Infrared light for acceleration detection
However, conventional accelerometers use a freely moving mass setting relative to a fixed reference point, the new NIST accelerator uses infrared light to detect changes in the distance between two highly reflective surfaces. Equivalent to the test mass – the mass that moves freely in normal accelerators – is supported by a mirror surface in the new NIST device. The other is a fixed concave mirror specifically made for the application.
With both reflective surfaces and the gap between them, a special wave-infrared light can bounce back and forth between the mirrors. The wavelength of the lasers, determined by the distance between the surfaces, is measured and used to determine acceleration.
To further monitor the resonant wave from the cavity, researchers placed a single-frequency laser locked in the enclosed space.
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