Invited article

• Verfasst von: Müller, Niklas [VerfasserIn]
• Verfasst von: Brückner, Lukas [VerfasserIn]
• Verfasst von: Motzkus, Marcus [VerfasserIn]
• Titel: Invited article
• Titelzusatz: coherent Raman and mid-IR microscopy using shaped pulses in a single-beam setup
• Verf.angabe: Niklas Müller, Lukas Brückner, and Marcus Motzkus
• E-Jahr: 2018
• Jahr: 27 July 2018
• Umfang: 11 S.
• Fussnoten: Gesehen am 13.05.2019
• Titel Quelle: Enthalten in: APL photonics
• Ort Quelle: Melville, NY : AIP Publishing, 2016
• Jahr Quelle: 2018
• Band/Heft Quelle: 3(2018,9) Artikel-Nummer 092406, 11 Seiten
• ISSN Quelle: 2378-0967
• DOI: doi:10.1063/1.5030062
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1665274700

Abstract

The possibility to exploit shaped ultrabroadband laser pulses for molecular coherent control offers a unique implementation of numerous nonlinear spectroscopic methods in one setup. Nonlinear processes, such as coherent Raman microscopy, second harmonic generation, or two-photon fluorescence, which have been applied in many different applications in both the material and life sciences, can be selectively addressed and optimized just by changing the phase imprinted by a programmable pulse shaper. Here, the experimental realization of this concept for multimodal nonlinear microscopy is discussed and the successful implementation of adaptive spectral focussing schemes not only for nonlinear Raman but also for difference frequency generation based mid-infrared (Mid-IR) spectroscopy using a single broadband pulse from a Ti:sapphire laser is shown. Flexible pulse shaping enables tuning of the resonance frequency and the spectral width of the excitation. By variation of the instantaneous frequency difference and the amount of chirp, the experiment can be optimized to achieve high resolution spectroscopy reaching up to 20 cm−1. Matching the resolution of the experiment with the linewidths of the sample on the other hand optimizes the contrast for imaging at high signal levels. The combination and flexible switching between Raman or mid-IR excitation for spectroscopy and microscopy is demonstrated on alkynes, polymer films, and skin tissue. The simple addition of this complementary modality to an existing nonlinear microscope is a further step toward an all-purpose laser excitation source for multimodal microscopy.