V. Petrov et al., Temperature tuned noncritical phase-matching in Li2B4O7 for generation of CW laser radiation at 244nm, ELECTR LETT, 35(9), 1999, pp. 721-722
Using temperature tuning in Li2B4O7 at 90 degrees phase-matching, efficient
extracavity second harmonic generation of up to 8mW CW laser power at 244n
m is reported.