Pulse Shaping

Principles of nonlinear microscopy and application possibilities in dermatology

“…Ekkor az optikai közeg polarizáltsága nemlineárisan függ a fény elektromos terétôl. Impulzusüzemû lézerek esetében a lézer energiája az egyes, viszonylag ritkán egymást követô lé-zerimpulzusokban koncentrálódik, ezért ezekben a léze-rekben gyakran tapasztalunk nemlineáris jelenséget, -gyakran a lézermûködés is ezeken a folyamatokon alapul (5). Számos nemlineáris optikai folyamat alkalmas bioló-giai minták in vivo vizsgálatára, mint például a kétfoton abszorpciós fluoreszcencia (TPEF), a másodharmonikus keltés (SHG) vagy a koherens anti-Stokes Raman szórás (CARS).…”

Enhanced temporal resolution in femtosecond dynamic-grating experiments

“…This is an advantage over conventional singlepump-single-probe experiments, 9 where optimal resolution is only obtained when the pulses propagate collinearly and deviation from collinearity causes the resolution to deteriorate as a result of the transverse dimensions of the pulses. 7,10 Experiments are conducted in calcium fluoride ͑CaF 2 ͒ samples to verify our theoretical prediction. Another advantage of this configuration is that the separation of the diffracted probe pulse and the pump pulses increases the signalto-noise ratio of the measurements.…”

“…Such dynamic gratings have already been the subject of several books. 6,7 In this article, the coupled-mode equations are solved for an undepleted, Bragg-matched probe pulse in the case of a Kerr nonlinearity, which can be regarded as instantaneous compared with the pulse duration ͑Ϸ200 fs͒. 8 The pumpand-probe trace thus obtained sets a limit on the achievable temporal resolution and the theoretical investigation presented in this article reveals that the temporal resolution of this pump-and-probe technique remains almost undegraded even when the angular separation between pulses is increased.…”

Development of a nonlinear nanoprobe for interferometric autocorrelation based characterization of ultrashort optical pulses

“…By assuming a linearly chirped Gaussian pulse profile E͑t͒ = exp͓−͑1+i␣͒͑t / G ͒ 2 ͔ the pulse width retrieved from this interferometric autocorrelation trace is about 120 fs ͑full width at half maximum͒ and a chirp parameter ␣ around 1.9 is estimated. 6 The theoretical curve ͑properly scaled and shifted͒ obtained by using these parameters is also shown for comparison ͑red dots͒. It should be noted that the baseline of the interferometric autocorrelation curve is not even on both sides.…”