Collinear ultra-broadband parametric fluorescence generated from 10%-chirped quasi phase matched device

In this paper, we introduce the experiment which gives the ultra-broadband parametric fluorescence from chirped-QPM device which extends approximately from 790nm to 1600nm towards the generation of mono cycle frequency-entangled photon pairs. The sample is 2cm-long SLT crystal with the magnesium oxide concentration of 1.0mol-% (MgSLT). Compared with the un-doped SLT, 10% chirping of the poling period (from 8.000μm to 8.825μm) of MgSLT crystal suffices to span larger phase matched wavelength range with the same sample length and pump wavelength. This was achieved for 1st-order QPM with collinear type-0 phase matching condition. Fig.1 shows the comparison between theory and experimental results using cw-pump beam (wavelength: 532nm). Green data calibrates the quantum efficiencies of detectors and diffraction efficiencies of gratings used in the experiment. The observed spectrum extends from 790nm to 1600nm. We will also discuss the effect of the focusing parameter and temperature dependence.