If you take a step back and look at what we know about the Universe you’ll quickly realize that ALL our knowledge about distant space comes from measuring light that is emitted by far-away astronomical objects.Thus any experimental technique that promise to dramatically increase the accuracy and stability of measuring light is a big deal for observational astronomers.如果你退后一步，看看我们所知道的宇宙你会很快认识到，我们的所有知识，遥远的空间来自于测量光发射的是遥远的天文objects.Thus任何实验技术的承诺，大幅增加的准确性和稳定性的测量轻是一个很大的交易观测的天文学家。 In a recent issue of Science such a big deal was published.在最近的问题， 科学这样一个大问题已经出版。 It’s called a Laser Frequency Comb and works by overlaying laser pulses of extremely short duration and extremely stable recurring frequency on top of the optical spectrum of the astronomical object under investigation.这是所谓的激光频率梳和工程的覆盖激光脉冲的极短的时间长短和极其稳定的经常性频率最高的光学光谱天文对象进行调查。 In essence, this technique allows the measurement of tiny variations over long periods of time in the frequency of light emitted by astronomical objects.从本质上讲，这种技术可以测量的微小变化很长一段时间内的频率发出的灯光天文物体。
Space is expanding, so that two objects that are separated by a certain distance drift apart with a speed that is proportional to the separation distance: The further an object is away from us the faster it moves away from us.空间正在扩大，因此，两个物体分开了一定的距离渐行渐远的速度是成正比的分离距离：进一步的对象是远离我们的移动速度远离我们。 So, if you could measure the red-shift of this object over some time, then you would be able to detect that said red-shift increases as the object moves away further and further.因此，如果您可以衡量红移这一物体一段时间，那么你就能够侦测到说红移增加为对象摆脱进一步，并进一步。 You would not need to reference the red-shift in the object’s spectral lines to some calibration source that was measured here on earth, as is done currently.你不会需要参考红移在该对象的光谱线的一些校准源，在这里测量地球上，这是目前做。 Think of this as an improved laser gun for your local traffic cop who will not only be able to tell your exact speed, but also whether you were slowing down or accelerating when he pointed the laser at you.认为这是一种改进激光枪的当地交通警察谁将不仅能告诉你确切的速度，而且也不管你是减慢或加速时，他指出激光你。
This technique promises to revolutionize deep-space astronomy AND near space astronomy as it will become possible to detect planets moving around their primary star, at least if the orbit is roughly within the line-of-sight from earth.这一技术有望带来革命性深层空间天文和空间天文附近，将成为可能发现行星的移动他们的主要球星，至少如果轨道大约是在视线从地球。 Exciting times.激动人心的时刻。
The basics of a laser frequency comb. A mode-locked laser creates femtosecond pulses at gigahertz frequencies, ƒ rep ( top ), that are synchronized with an atomic clock. 基本的激光频率梳。阿锁模激光飞秒脉冲创建于千兆赫的频率， ƒ 代表 （顶部） ，这是一个同步的原子钟。 A spectrum of the pulses ( bottom ) is composed of many modes that are uniformly spaced in wavelength (or frequency) and cover a spectral bandwidth given roughly by the inverse of the pulse duration.频谱的脉冲（下）是由许多模式，是均匀分布的波长（或频率） ，并涵盖了光谱带宽提供大约由逆的脉冲持续时间。 Each mode’s wavelength (or frequency) does not have to be measured, but instead is given by a mathematical relation that includes ƒ rep , known a priori with very high accuracy.每个模式的波长（或频率）没有来衡量，而是给出了一个数学关系，其中包括ƒ 代表 ，事先已知非常高的准确性。 Laser frequency combs could therefore become the perfect wavelength calibration technique for astrophysical experiments that require high accuracy and long-term stability.激光频率梳因此可以成为完美的波长校准技术，天体物理实验，要求精度高，长期稳定。
CREDIT: ADAPTED BY P. HUEY/ SCIENCE信用：适应由P.惠/科学
