crystal, allowing some tuning of the resolution for pulses of different bandwidths. To understand the performance of a given crystal, a factor, A, is introduced to the GVD and GVM conditions, which can be rearranged to get In the above equation, the TBP has been assumed to be approximately equal to 1, indicating a near-transform limited pulse. If A is much greater than 1 then the condition is well satisfied. The case where A equals 1 is considered the cutoff for satisfying the condition and is the edge of where the crystal can resolve a pulse. Typically, A is chosen as a conservative number such as 3. These equations can be used to determine the working limits for a given setup as a function of wavelength. See also Frequency-resolved optical gating References Nonlinear optics Lasers Optical metrology Ultrafast spectroscopy