US 6,982,999 B1
Multipass second harmonic generation
Bruce Richman, Sunnyvale, Calif. (US); Chris W. Rella, Sunnyvale, Calif. (US); and Konstantin Vodopyanov, San Jose, Calif. (US)
Assigned to Picarro,Inc., Sunnyvale, Calif. (US)
Filed on Jan. 21, 2003, as Appl. No. 10/349,379.
Int. Cl. H01S 3/10 (2006.01)
U.S. Cl. 372—22 24 Claims
OG exemplary drawing
 
1. Apparatus for frequency-doubling optical radiation, the apparatus comprising:
a) an optically nonlinear medium that receives a first beam of optical radiation having a first frequency, wherein the first beam makes N passes through the nonlinear medium, where N is an integer ≧2, to thereby generate a second beam having a second frequency substantially equal to twice the first frequency; and
b) a telescope subassembly having an ABCD matrix with matrix coefficients substantially A=−1, B has any real value, substantially C=0 and substantially D=−1, for receiving and coupling the first and second beams, emitted from the nonlinear medium after a pass number J, back into the nonlinear medium for a pass number J+1, where 1≤J<N, wherein the second beam issues from the telescope subassembly.