Abstract The goal of this research program is to develop femtosecond source technologies that move beyond mode- locked lasers and to demonstrate these new techniques with multiphoton microscopy based on adaptive excitation. High speed multiphoton imaging based on adaptive excitation requires wavelength and pulse pattern agility that is not currently available. Traditional laser-based sources, moreover, are limited in wavelength, repetition rate, complexity, and cost. The research proposed will first demonstrate the desired versatile femtosecond source and then apply this source to multiphoton microscopy based on adaptive excitation. The research program is based on three major innovations: (1) high quality femtosecond pulse trains can be generated through optical modulation and novel nonlinear pulse compression and cleaning techniques, (2) high energy wavelength-agile amplification can be achieved in fiber through broadband intra-pulse phase matching of chirped pulses, and (3) adaptive excitation enables more than order-of- magnitude improvements to the speed of multiphoton microscopy with a high power source supporting the combination of an arbitrary wavelength and pulse pattern, such as with the proposed robust fiber-format technique enabled by innovations (1) and (2). Our aim is to enable more than an order-of-magnitude improvement to frame rates at the ultimate depth limits to imaging with a novel source that is significantly more accessible than previous technologies. Successful completion of this program will have major impact for biomedical research directions which employ ultrashort pulse technology, such as deep tissue imaging.