Generator of erbium and CO2 laser combination frequencies

摘要

Abstract: Sum and difference frequency generators of Er$+3$PLU$/:CaF$- 2$/ ($lambda $EQ 2.76 $mu@m), Er$+3$PLU$/:YAG ($lambda $EQ 2.94 $mu@m), and cw CO$-2$/ lasers with ZnGeP$-2$/ and CdSe single crystals has been developed to enlarge the possibilities of spectroscopic systems based on CO$-2$/ lasers. The generated spectra overlapped the ranges from 2.1 to 2.3 and from 3.7 to 4.3 $mu@m which coincide with the two main atmosphere transparency windows. The energy effectiveness of sum frequency generation with 4.5 mm ZnGeP$-2$/ crystal realized is about 3% at phase-matching angle of 52$DGR and 12% for difference frequency generation in 40-mm CdSe crystals at phase-matching angle of 72$DGR@40'. The latter source, in particular, may be used in CH$-4$/ lidar.!11