Frequency Stability: What Does 2 Parts in 10E10 Mean?

In summary, the frequency stability of a laser is commonly expressed as 2 parts in 10E10, which means that the frequency shifts 0.02nm from the mean wavelength on each side. This shift is typically measured as a normalized shift with respect to the central frequency of the laser and is dimensionless.
  • #1
Stu165
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Does anyone know what it means to say that the frequency stability of a laser is 2 parts in 10E10, I gather that it means that the frequency shifts 0.02nm each side of the mean wavelength. But I can't find any resources that use the term parts.
 
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  • #2
The shift is usually expressed as a normalised shift w.r.t. the central laser frequency.

[tex] \frac{\Delta\nu}{\nu_0} [/tex]

This quantity is dimensionless and thus has no units.

Claude.
 
  • #3
I know that equation and all the coherence stuff, it's just the terminology of 2 parts in 10e10, has thrown me and how to get the shift from that.
 
  • #4
Well,

[tex] \frac{\Delta\nu}{\nu_0} = 2 \times 10^{-10}[/tex]

If you know the central frequency of the laser, you can figure out the exact amount of shift.

Claude.
 
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FAQ: Frequency Stability: What Does 2 Parts in 10E10 Mean?

What is frequency stability?

Frequency stability refers to the ability of a system or device to maintain a consistent frequency over time.

What does "2 parts in 10E10" mean in terms of frequency stability?

"2 parts in 10E10" is a measure of frequency stability and indicates that the frequency will change by no more than 2 parts per 10 billion over a given period of time.

Why is frequency stability important?

Frequency stability is important because it ensures that a system or device can accurately and consistently perform its intended function. In many scientific and technological applications, a stable frequency is crucial for accurate measurements and reliable performance.

How is frequency stability measured?

Frequency stability is typically measured using a frequency counter or a phase noise analyzer. These instruments compare the output frequency of a system or device to a stable reference frequency and calculate the difference over time.

What factors can affect frequency stability?

Factors that can affect frequency stability include temperature changes, mechanical vibrations, and electronic noise. These external influences can cause fluctuations in the frequency of a system or device, leading to a decrease in stability. Proper design and shielding can help minimize these effects and improve frequency stability.

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