Frequency doubling of He - Ne laser radiation at 632.8 nm

Abstract

Second harmonic generation (SHG) obtained using a potassium dihydrogen phosphate (KDP) nonlinear crystal from a CW He-Ne laser as a pump source, which emits at 632.8 nm, is reported. The SHG efficiency at the power of the He-Ne laser utilized (18 mW) and the fundamental beam waist available (0.1 mm), was evaluated theoretically; the same efficiency was measured experimentally obtaining a value of (3.7-0.1)×10 −7 , in good agreement with theoretical predictions.

Second harmonic signal generation by low power laser for the use of harmonic microscope

“…Hence the effective area of the SHG is smaller to the diffraction limited spot of the fundamental light. Therefore in the next step of the experiment, the frequency doubling due to SHS together with diffraction limited laser spot will be used to develop a superresolution microscope along with the second harmonic mapping of a biological sample [1,[4][5][6][7][8][9].…”