Jitter

Brownian motion The ceaseless jittering motion of colloidal particles caused by the impact of solvent molecules. 

Linearly polarized, near-diffraction-hmited, mode-locked 1319 and 1064 nm pulse trains are generated in separate dual-head, diode-pumped resonators. Each 2-rod resonator incorporates fiber-coupled diode lasers to end-pump the rods, and features intracavity birefringence compensation. The pulses are stabilized to a 1 GHz bandwidth. Timing jitter is actively controlled to < 150 ps. Models indicate that for the mode-locked pulses, relative timing jitter of 200 ps between the lasers causes <5% reduction in SFG conversion efficiency. 

Theoretical level populations. Sinee there are population variations on time seale shorter than some level lifetimes, a complete description of the excitation has been modeled solving optical Bloch equations Beacon model, Bellenger, 2002) at CEA. The model has been compared with a laboratory experiment set up at CEA/Saclay (Eig. 21). The reasonable discrepancy when both beams at 589 and 569 nm are phase modulated is very likely to spectral jitter, which is not modeled velocity classes of Na atoms excited at the intermediate level cannot be excited to the uppermost level because the spectral profile of the 569 nm beam does not match the peaks of that of the 589 nm beam. 

A simple expression for the signal-to-noise ratio (SNR) of a measurement of visibility amplitude involves several parameters relating to interferometer and source properties. The formula presented here provides the fundamental sensitivity limit. Contrast loss arising from instrumental jitter and seeing are summarised in a common factor system Strehl , which is the ratio of the number of photons which can be used for a coherent measurement to the... 

Finally, the calculations are repeated 100 times (with variation of 0 to simulate 0-jitter within the resolution window) to obtain statistically reliable means and standard deviations for the diverse combinations of factors (Table 4.23). 

Infantile spasms A seizure syndrome that occurs in infants less than 1 year of age. It is characterized by a specific EEG pattern and spasms or jitters and is also known as West s syndrome. Infants with infantile spasms often develop other seizure types and epilepsies later in life. 

Lecos C. Caffeine Jitters Some safety questions remain. FDA Consumer. December 1987-January 1988. 

The price to pay for getting the higher intermediate frequency in such a convenient way would be the less clock-jitter tolerance, so that the apparent resolution of the resonance line can be degraded compared with that obtained in the conventional detection scheme. For this reason, we demonstrated the high-resolution liquid-state NMR experiment, in which the resonance line width was on the order of Hz. In fact, we observed a drift of the peak position when we used a less stable clock... 

Another important property of PMTs is the pulse height distribution. The amplification of individual photoelectrons by the PMT is a stochastic process that causes variations in the gain of individual photoelectrons. As a result significant jitter in the amplitude of the output pulses is observed, see Fig. 3.6. These pulse height variations can be more than a factor of 10. The lowest pulse heights mainly consist of (thermal) noise, indicated by the dashed line in Fig. 3.6. The pulse height distribution exhibits a peak corresponding to detected photons. The threshold level of the... 

There are several other sources of noise that are specific to lifetime imaging. In particular, noise related to the timing jitter of... 

Because of the low timing-jitter (down to 25 ps) TCSPC-based systems are often equipped with a MCP-PMT at detriment of acquisition speed (<106 counts per second). On the other hand, a TG-SPC system equipped with four gates and a fast PMT (10 MHz) could be slower than a TCSPC at low count-rates (<100 kHz), because of a lower photon-economy. However, already at 1 MHz, the former would be almost three times faster and more the one order of magnitude faster at 10 MHz. 

Why should they There is no guarantee that a part must switch without excessive jitter, for example. These are only implied expectations you may have when you buy an IC. Further, what exactly constitutes excessive Every switcher has some jitter ... 

Figure 9-1 Understanding the Difference Between Jitter and Clock Instability... 

Now you can clearly distinguish between clock instability and excessive (trailing edge) jitter. Remember, also, that you can set a digital scope to report the frequency of the waveform. Watch that number closely and make sure it is quite stable, otherwise you have clock instability. 

Once you have a stable clock, you might like to check the jitter. So how much jitter is acceptable In an AC-DC power supply with no PFC correction, especially at low line, the input voltage ripple is quite high. As this instantaneous input voltage moves up and down, a... 

Check SW node on scope while test is in progress The jitter" should not be more than -10% of the time period of the switching cycle, and not less than -2%. Otherwise adjust Output amplitude / attenuation settings on Spectrum Analyzer. 

---