Second harmonic generation of a new nonlinear optical material:urea L-malic acid

Second harmonic generation （SHG） of a new organic optical crystal-urea L-malic acid （ULMA） was studied. A comparison of SHG efficiency of ULMA and KDP at a fundamental wavelength of 1064 nm using the Kurtz powder method demonstrated that the second order nonlinear coefficient of ULMA is 1 57 times of that of KDP,and the damage threshold of ULMA is relatively higher Finally,both Type Ⅰ and Type Ⅱ phase match angles of the biaxial crystal ULMA were calculated.