fokirealty.blogg.se - Gain bandwidth product

#GAIN BANDWIDTH PRODUCT FULL#

(Note that the pulse duration achievable actually depends on the “curvature” of the gain spectrum within the range of the pulse spectrum, and also on the magnitude of gain.) It can limit the pulse duration of a mode-locked laser.It can limit the range for wavelength tuning.The gain bandwidth of the gain medium of a laser, or of an optical parametric amplifier, can be important e.g.

Such a quantity can be used, e.g., in the Haus Master equation. the generation of ultrashort pulses with mode locking) the relevant quantity is not the total width of the gain region, but rather the “curvature” of the gain curve near its maximum.įor a given spectral shape, that curvature is directly related to the gain bandwidth, and some effective gain bandwidth can be defined to quantify that mentioned curvature. the width of the range where the gain is at most 3 dB (or 10 dB) below its maximum valueīecause of these manifold definitions, which can lead to substantially different values, the specification of a gain bandwidth is meaningful only when the definition used is indicated.Īdditional difficulties arise when the shape of the gain spectrum is complicated, e.g.the width of the logarithmic gain or the amplification factor, measured at a different level (e.g., where the gain has decayed to 1/e ≈36.8% or to 10% of the maximum gain).

#GAIN BANDWIDTH PRODUCT FULL#

the full width at half-maximum (FWHM) of the amplification factor.

the full width at half-maximum (FWHM) of the logarithmic gain, measured in decibels.

Unfortunately, there is a lot of confusion about the exact meaning of the term gain bandwidth (also called amplification bandwidth), because the gain of, e.g., a laser amplifier decreases fairly smoothly, and also there are different ways of quantifying gain, so that there is not a single straightforward definition.