This month is considered as the production month of cell phone jammer

 This month is considered as the production month of cell phone jammer .
Therefore, the transmission wavelength of great value and the value of a one to one relationship between the cavity length. As long as there is a certain level of voltage to change the cavity length, can make all the different laser wavelengths (or frequencies) of the model in turn generate significant coherence through the formation of scanning. But it is worth noting that if the incident light wavelength range exceeding a certain limit, the applied voltage, although long linear cavity can change, but a cavity length may be determined by several different wavelengths to produce coherent mode while greatly, resulting in heavy order. For example, when the cavity length changes dramatically when to make λb, λa will be great again, there is order in the λd k and k +1 in order to meet the great λa same conditions, two different modes are also swept out, superposition together, so there is a scanning interferometer itself is not re-order the limited wavelength range. The so-called free spectral range (SR) refers to the scanning interferometer can not re-order sweep out the maximum wavelength difference or frequency difference, with ΔλS.R. or ΔvS.R. said. If the case ld is just the starting point for re-order, then λd-λa that this interferometer free spectral range value. In pattern analysis experiments, because we do not want (12) in the re-order phenomenon, so use the scanning interferometer, we must first know its ΔvS.R. and analysis of the laser frequency range to be Δv, and to ΔvS.R .> Δv, in order to ensure that the surface does not re-order spectrum, ie the cavity length and mode of wavelength or frequency is between one relationship. The quality assurance of cell phone jammer should be strictly performed.
Cavity free spectral range can also be used to describe the change in length, that the change in cavity length is λ / 4 when the corresponding scan range. Because light in a confocal cavity was x-type, four times the distance of the optical path difference is exactly equal to λ, the number of changes in an intervention order. In addition, also see, when they meet ΔvS.R.> Δv conditions, if the applied voltage is large enough, can make the change in cavity length is λ / 4 for i times, then the interference will be i-scan sequence, Therefore, the laser mode will periodically repeated sequence in the interference k, k +1 ,..., k + i in Figure 6 below. Constant F is used to characterize the fine scanning interferometer resolving power of the argument. It is defined as: free spectral range and the minimum width ratio of the resolution limit, ie in the free spectral range can distinguish between the maximum number of lines. The theoretical formula for the fine constant. The document describes the quality control requirement of cell phone jammer clearly.