| 摘要 |
The invention concerns the optimization of the transformation rate(efficacy)during optical frequency conversion of laser beams with ultrashort light pulses in optically non−linear media,for example,a crystal(56),and,therefor,comprises the arrangement of a double refracting crystal(54),on the radiation path,in front of the optically non−linear medium(56).The length of the double refracting crystal(54)is selected,and the orientation of its optical axis relative to the propagation direction of the laser beams involved in the frequency conversion is adjusted,such that modification in place,time and direction of the incidence of the laser pulses(14)and(16)on the optically non−linear medium,caused by the double refracting crystal(54),and the resulting spatial and temporal overlapping modification of the laser pulses in the optically non−linear medium(56)for frequency conversion in the crystal(56),produce a conversion rate higher than the conversion rate obtained without double refracting crystal(54). |
