Pitfall in autocorrelation measurements of laser radiation.

Spectrally broad laser radiation from continuous wave (cw) lasers can exhibit second-order autocorrelation traces virtually indistinguishable from those of mode-locked lasers. Consequently, based only on autocorrelations, one might erroneously conclude that a cw laser is mode-locked. This pitfall in interpretation can be avoided by carefully characterizing radio frequency transients and spectra.

Nonlinear compression of few-cycle multi-mJ 5 µm pulses in ZnSe around zero-dispersion.

We present a compact nonlinear compression scheme for the generation of millijoule few-cycle pulses beyond 4 µm wavelength. For this purpose 95 fs pulses at 5 µm from a 1 kHz midwave-IR optical parametric chirped pulse amplifier (OPCPA) are spectrally broadened due to a self-phase modulation in ZnSe. The subsequent compression in a bulk material yields 53 fs pulses with 1.

Creating the perfect plasmonic wave.

Exploiting a plasmonic resonance, near-perfect grating structures have been reported, with a regularity that exceeds typical commercially available diffraction gratings.

Kinetics of excitation transfer from Cr to Fe ions in co-doped ZnSe.

The transfer of electronic excitations from Cr to Fe ions in co-doped epitaxially grown ZnSe is studied by time-resolved photoluminescence (PL) spectroscopy with unprecedented sub-10 ns time resolution. Upon excitation of Cr ions by a picosecond pulse at 2.05 µm wavelength, PL from Fe ions displays a delayed onset and a retarded decay in comparison to Fe PL directly excited at 3.

Milliradian precision ultrafast pulse control for spectral phase metrology.

A pulse-shaper-based method for spectral phase measurement and compression with milliradian precision is proposed and tested experimentally. Measurements of chirp and third-order dispersion are performed and compared to theoretical predictions. The single-digit milliradian accuracy is benchmarked by a group velocity dispersion measurement of fused silica.