Category Technology/Electronics

Lasers + Anti-lasers: Marriage opens door to Development of Single Device with Exceptional Optical Capabilities

Schematics above show light input (green) entering opposite ends of a single device. When the phase of light input 1 is faster than that of input 2 (left panel), the gain medium dominates, resulting in coherent amplification of the light, or a lasing mode. When the phase of light input 1 is slower than input 2 (right panel), the loss medium dominates, leading to coherent absorption of the input light beams, or an anti-lasing mode. (Credit: Zi Jing Wong/UC Berkeley)

Scanning electron microscope image of the single device capable of lasing and anti-lasing. Indium gallium arsenide phosphide (InGaAsP) material functions as the gain medium, while the chromium (Cr) and germanium (Ge) structures introduce the right amount of loss to satisfy the condition of parity-time symmetry that is required for lasing and anti-lasing. (Credit: Zi Jing Wong/UC Berkeley)(From left) Berkeley researchers Xiang Zhang, Zi Jing Wong, Jeongmin Kim and Yuan Wang stand next to the optical setup they designed to demonstrate both lasing and anti-lasing in a single device. (Credit: Marilyn Chung/Berkeley Lab)

  1. Schematics above show light input (green) entering opposite ends of a single device. When the phase of light input 1 is faster than that of input 2 (left panel), the gain medium dominates, resulting in coherent amplification of the light, or a lasing mode. When the phase of light input 1 is slower than input 2 (right panel), the loss medium dominates, leading to coherent absorption of the input light beams, or an anti-lasing mode. (Credit: Zi Jing Wong/UC Berkeley)
  2. Scanning electron microscope image of the single device capable of lasing and anti-lasing...
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Scientists present the most Accurate time Measurements of Quantum Jumps to date

Ein kurzer Laserpuls ionisiert ein Helium-Atom und kann den Zustand des verbleibenden Elektrons verändern.

A short laser pulse can ionize a helium atom and change the quantum state of the remaining electron.

When a quantum system changes its state, this is called a quantum jump. Usually, these quantum jumps are considered to be instantaneous. Now, new methods for high-precision measurements allow us to study the time evolution of these quantum jumps. On a time scale of attoseconds, there time structure becomes visible. It is he most accurate time measurement of quantum jumps to date. Quantum particles can change their state very quickly, ie “quantum jump”. An atom, for example, can absorb a photon, thereby changing into a state of higher energy. With new methods, developed at TU Wien (Vienna), it is now possible to study the time structure of such extremely fast state changes...

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Light Drives Single-molecule Nanoroadsters

A scanning tunneling microscope image shows two three-wheeled nanoroadsters created at Rice University and tested at the University of Graz. The light-activated roadsters, next to their molecular models, reached a top speed of 23 nanometers per hour. Credit: Alex Saywell/Leonhard Grill

A scanning tunneling microscope image shows two three-wheeled nanoroadsters created at Rice University and tested at the University of Graz. The light-activated roadsters, next to their molecular models, reached a top speed of 23 nanometers per hour. Credit: Alex Saywell/Leonhard Grill

Scientists are driving 3-wheeled, single-molecule “nanoroadsters” with light and, for the first time, seeing how they move. The Rice lab of nanocar inventor and chemist James Tour synthesized light-driven nanocars 6 years ago, but with the aid of experimental physicists in Austria, they’re now able to drive fleets of single-molecule vehicles at once...

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Energy-Saving Data Glasses

Fraunhofer researchers have developed an energy-saving display that reduces the power consumption to a fraction. Credit: © Photo Fraunhofer FEP

Fraunhofer researchers have developed an energy-saving display that reduces the power consumption to a fraction. Credit: © Photo Fraunhofer FEP

Data glasses mirror information to the eye without interfering with the wearer’s vision. However, the battery runs down quickly as the electronics consume a great amount of electricity while playing back images. Fraunhofer researchers have developed an energy-saving display that reduces the power consumption to a fraction. Via a small display, data glasses present the eye with information or images which are received using a radio link from the frame of the glasses.

The big advantage: With data glasses, the wearer’s hands are free – in contrast, a smartphone has to be held in the hand. This may be interesting for mechanics...

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