To make a light-guiding fiber only in one direction, a method has been more than one. Recently, the American University of Illinois at Urbana – Champaign researchers have for the first time proved the Brillouin scattering caused by transparent (BSIT) can achieve this effect, BSIT effect allowing light to propagate forward, and backward propagation of light is strongly absorbed It can also make the fiber optical accelerate, slow down or even stop. This non-interactive nature of the basic conditions for constructing insulators and circulators, and is one of the essential tools for optical design. Related papers published in the recent “Nature Physics” magazine.
In the incident power is not high, the fiber material molecule Brown Games acoustic noise. Brillouin – scattering Mandelstam was first discovered in the early 1920s, it is a light and sound waves caused by stretching the fiber material by electric light pressure coupled together, and the occurrence of sound and light scattering. “The basic physical processes underlying BSIT present in all solid, liquid, gas or plasma.” First author, University of Illinois graduate student phonetic said.
According to physicist organization network on January 29, researchers reported experimental demonstration BSIT phenomena tool is very simple, just a glass ring glass fiber and next. “With a micro-resonator (small glass ring), and fiber by it very close, which can absorb specific wavelengths of light.” Associate Professor of Mechanical Science and Engineering, University of Illinois Gaurav? Barr said, “and by BSIT effect can eliminate this opaque, such as next to add a bunch of specific wavelength of the laser, allows the system to become clear again. This is a new kind of physical processes never seen before. The most important is that we find, BSIT is a non- Interactivity phenomenon – can only lead to transparent in one direction, while in the other direction, the system will still be absorption of light. ”
In most acoustics, electromagnetism and thermodynamics, inversion symmetry (eg interactivity) is a basic principle. In some special equipment applications, engineers often use a variety of techniques to break interactivity. Existing non-interactive optical devices such as isolators and circulators, breaking through the magnetic field interaction. The material generating a magnetic field in the scale is difficult to manufacture the chip, in some systems, the magnetic field is also a source of interference.
“We have shown that a magnet can be obtained without an optical non-linear interaction methods can be implemented in any conventional optical material system, the current plant can be used for any commercial optics.” Barr said that the current bristol insulation is non-linear device, but also need to filter the scattered light, and BSIT is a linear non-interactive mechanism. BSIT also speed up and slow down the wave group velocity of light, physicists call “fast” light “slow” light. “Slow” light technology for quantum information storage and optical buffer device extremely useful. Someday, this buffer is expected to be incorporated into a quantum computer.