Compressing light – generation of strikingly short pulses

01.01.2014, 00:00

Newsletter 7

Laser pulses with extremely short durations (a few fs) are proving immensely useful in numerous scientific applications, such as the capturing of electron dynamics on extremely short timescales. By exploiting the unique qualities of noble gas-filled hollow-core photonic-crystal fibre (HC-PCF), we have demonstrated soliton self-compression of laser pulses down to durations of a few fs. In this process, the energy of a launched ~50 fs pump pulse at 800 nm is re-distributed adiabatically across a broad range of frequencies, merging in time into a single ultrashort pulse. This is possible because of weak anomalous dispersion, self-phase modulation and the optical shock effect. Since the core is filled with an inert gas, substantially higher pulse energy (? 10 µJ) can be handled compared to traditional solid-core fibre. Moreover, HC-PCF provides much stronger light confinement than traditional glass capillaries, enabling the hollow core diameter to be down-scaled without impairing the optical transmission. This allows intensities of TW/cm2 to be reached even at the moderate peak powers available from current generation high repetition-rate (hundreds of MHz) fiber and thin-disk lasers. The realization of a high average power, high repetition-rate ultrashort laser source is therefore one step closer.

Contact: kafai.mak(at)mpl.mpg(dot)de
Group: Russell Division
Reference: K. F. Mak et al., Opt. Lett. 38, 3592–3595 (2013).