Fig. 2

Laser-assisted emission measurement setup. The 50 fs long pulses at wavelength of 800 nm were provided by Tissa 50 Ti: sapphire oscillator and amplifier. Beam diameter was fixed to 4 mm by the aperture A. Nonlinear crystal SHG provided second harmonic pulses at the wavelength of 400 nm. The fundamental and second harmonic beams are orthogonally polarized. The excitation pulse wavelength was selected by co-aligned grid polarizers P1 and P3. The energy of the incident pulse was controlled by the Glan polarizer P2. The energy of the incident pulse was measured by silicon photodiode PD, which was calibrated by a power meter for each wavelength and polarization of the incident pulse