Fibre-based source of femtosecond pulses tunable from 1.0 to 1.3 (mu)m

Tunable short-pulse generation in the spectral range 1030-1330 nm with an all-fibre source is demonstrated. A compact system with a femtosecond Yb fibre oscillator and a photonic crystal fibre relies on the soliton self-frequency shift to cover the wavelengths of primary interest to biological/biomedical imaging deep in tissue. Continuous tuning of <100 fs pulses with energies in the range 0.1-0.5 nJ is accomplished by adjusting the pulse energy.