Nonlinear optical microscopy with vibrational contrast

Nonlinear optical techniques which provide vibrational contrast have gained increasing attention in microscopy during the last two decades. After outlining the potential of these techniques, we give a brief introduction to coherent anti-Stokes Raman scattering, stimulated Raman scattering and sum frequency generation and discuss their suitability for contrast generation in optical microscopy. The rapid developments in these fields during the last decade have resulted in many different applications. Three exemplary application areas will therefore be presented in the last part of this manuscript.