Abstract

Gain-switched distributed feedback (DFB) laser diodes can produce pulses in the sub-100 picosecond range. The spectral width is less than 0.2 nm under pulsed operation. This makes them well suited for optical amplification and nonlinear frequency conversion [1]. In this work we characterize a setup based on a fiber coupled freely triggerable DFB seed laser at various repetition rates and pulse energies operating at 1062 nm. Amplification takes place in a single-stage Ytterbium-doped fiber amplifier. The output beam is then focused into 10 mm long periodically poled lithium niobate (PPLN) for second-harmonic generation (SHG). The waist radius in the crystal is 23 pm, which is close to optimum focusing for the given crystal length [2]

© 2011 Optical Society of America