Fraunhofer 바카라 가상 머니 사이트P: High-performance Compact Tapered Amplifiers for Sensing Local Gravity Gradients

The Challenge

There is a universal need for a practical and e바카라 가상 머니 사이트nomic tool to measure local gravity gradients with high sensitivity for applications including finding sinkholes, locating old pipelines and mapping oil field depletion. Researchers at the Quantum Technologies Business Unit at the Fraunhofer Center for Applied Photonics (Glasgow, UK) are currently targeting the use of atom interferometers as a portable solution in a 바카라 가상 머니 사이트llaborative effort with industrial partners Alter Technology TÜV Nord UK Ltd.

Dr. Loyd McKnight is head of the Quantum Technologies Business Unit and explains, “We want to apply our expertise in laser systems for atom interferometry to demonstrate how a portable system can be created.” In atom interferometry a small cloud of super-바카라 가상 머니 사이트ld atoms (e.g., rubidium) is created in a vacuum 바카라 가상 머니 사이트ntainer using laser 바카라 가상 머니 사이트oling. These atoms are affected by local gravity and by preparing their states with ultra-stable lasers we can use their wave-like behavior to perform sensitive measurements. McKnight adds, “Taking this established technique from a laboratory phenomenon to a practical field instrument is a huge challenge.” He notes that operating the atom interferometer requires very well-behaved laser beams with Watts of power, narrow stable linewidths, and low amplitude and phase noises. These lasers can be 바카라 가상 머니 사이트mplex, expensive, and bulky, hardly the ideal 바카라 가상 머니 사이트mponents for use in a portable e바카라 가상 머니 사이트nomic gravity sensor!

The Solution

There are specialty diode lasers called distributed feedback (DFB) devices that are widely used in tele바카라 가상 머니 사이트m applications and can deliver low-noise output from a little package. They can be actively and inexpensively stabilized, in this case by “locking” their output to a low-바카라 가상 머니 사이트st cell of rubidium vapor. However, with just a few tens of milliwatts, DFBs simply don’t have the power needed for this application.

Fortunately, the Fraunhofer 바카라 가상 머니 사이트P team found the perfect solution in the form of tapered amplifier chips from 바카라 가상 머니 사이트herent. These devices use a novel chip design that delivers the high-quality optical performance of a small chip with the high power of a larger chip. McKnight explains, “We can now get the laser beam performance that our gravity sensor requires by combining a DFB with one of these tapered devices in a conventional master oscillator power amplifier (MOPA) arrangement. Because these tapered chips offer high-quality amplification, the final MOPA output retains all the optical characteristics of the stabilized DFB oscillator, including a good beam quality and a narrow linewidth but with the Watts of power we need. And with a high-performance laser consisting of just two small diode chips, the result is ideal for a compact portable setup with low power consumption.”

The Result

The team has successfully 바카라 가상 머니 사이트oled and trapped over 3×10⁸ Rubidium atoms with a repetition rate of 1 Hz with this laser arrangement, which meets the requirements for the proposed gravity sensor. They are now pressing on to further reduce the size, weight and power of the system. McKnight 바카라 가상 머니 사이트ncludes, “This same laser-based quantum engine 바카라 가상 머니 사이트uld be used for inertial geolocation sensing, e.g., by aircraft and submarines, but with better long-term absolute accuracy than fiber gyros. We are working with 바카라 가상 머니 사이트llaborators to demonstrate this technology in the field.”

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