An extended cavity diode-pumped femtosecond Yb:KGW laser for applications in optical DNA sensor technology based on fluorescence lifetime measurements.

A reliable and power-scalable extended cavity diode-pumped passively mode-locked Yb:KGW laser generating ~200 fs long pulses at a repetition rate of 15 MHz was developed and characterized. The laser delivered up to 150 mW of average power at fundamental wavelength of 1040 nm, corresponding to a pulse energy of 10 nJ. The laser radiation was frequency-doubled in a single pass configuration within a nonlinear BIBO crystal to produce femtosecond green radiation at 520 nm with peak power of ~200 W. The generated second harmonic served as excitation source for optical DNA biosensor based on fluorescence lifetime measurements obtained using the time-correlated single photon counting technique.