Fig. 4
From: Pushing the mass limit for intact launch and photoionization of large neutral biopolymers
Molecular beam strength and desorption efficiency as a function of laser pulse duration. a Desorption economy: Gramicidin D was desorbed from a thin film. We compare the longevity of a typical sample spot under ultrafast desorption (300 fs at 343 nm, 15 µJ red full circles and line) and short pulse desorption (7 ns at 355 nm, 3 mJ, blue full squares and line). For the same surface area of 100 × 100 µm2, femtosecond irradiation yields approximately the same initial molecular beam signal but at substantially longer sample life time. The solid lines are exponential fits to the data, with a decay constant of τns = 27 and τfs = 676 min. b Desorption laser pulse duration: When varying the pulse duration of infrared light (1030 nm, 40 µJ on 100 × 100 µm2) irradiating gramicidin D (see inset), we find a smooth increase in the number of detected molecules when the pulse duration is ramped through a factor of 25. The solid line is a square root fit to guide the eye
