For a near transform limited 5fs pulse as from the venteon ultra propagating through 10mm of BK7 glass, the pulse would be already stretched to 360fs. Propagation through 1mm of fused silica would stretch the same pulse to approx. 20fs, the same as travelling through 2m of air at room temperature. As an example, to compensate for passing through 15mm of fused silica (which adds about 540fs² of GVD) four bounces, off a pair of DCM11 mirrors, are needed (one pair of DCM11 mirrors introduces approx. -130fs² of GVD, i.e. approx. -65fs² per mirror) Related to: gecco / venteon / taccor
