The influence of Er3+ and Er3 + /Yb3+ doping on Second harmonic generation in Er3+ and Er3+/Yb3+ doped fibers

Abstract

The SHG experiments were performed using a CW mode-locked (82MHz) and Q-switched (3kHz) Nd:YAG laser. The 532nm seeding SH pulse, produced by a KTP crystal, was about. 5% of peak pump power. In order to make high conversion efficiency and save preparation time, a new method of two-stage preparation was used. At first stage the method of 532nm seeding was used. After 10 minutes seeding, only the 1064nm pump pulse was used at second stage. It took 10 + 30 minutes for the SHG efficiency to reach a saturated level. The efficiency was higher than that of 532nm seeding preparation, and the preparation time was less than that of 1064nm-only-preparation. Several Er3+ and Yb3+/Er3+ fibers with various dopants and core-cladding index differences were prepared by the two-stage method, and the the measured maximum efficiency of SHG was 8.8%.