Femtosecond pulse generation using a fiber-based amplifier and a grism compressor

Abstract

Improper selection and control of the laser source's optical properties, such as wavelength and pulse duration, limit the potential of laser systems in multiphoton microscopy (MPM). In this work, we develop a fiber-based laser system whose properties may be suitable for MPM. It is based on the chirped pulse amplification system. We use a normal dispersion fiber to stretch a pulse, thulium- and terbium-doped fluoride (Tm:Tb:ZBLAN) fibers for amplification at the 1.7 µm window, and a grating-prism (grism) pair to compress the pulse. Through proper optimization of the grism compressor parameters, our system achieves an average power of approximately 1 W at megahertz repetition rates and compresses the pulse down to 259 fs. The generated sub-microjoule pulses may be able to enhance current imaging techniques and facilitate new investigations in in vivo microscopy.