L-Alanine is one of the members of amino acids family having excellent SHG related properties to be used in nonlinear optical applications. In the present study, we review the structural, optical and 2^nd order SHG related properties of solution grown L-Alanine and its doped forms. XRD analysis reports the noncentrosymmetric, orthorhombic structure of LA single crystals and no change in its basic structure is observed upon doping withmaterials like HCl, CdBr₂, Li₂SO₄, Co²⁺ etc. except in the case LA is doped with HNO₃, CdCl₂, Bi(NO₃)₃ and C₆H₃N₃O₇ in which LA admixtured forms was found be having monoclinic structure. Zwitterionic structure of LA and its doped forms was confirmed by the FTIR spectral analysis. Low value of dielectric loss for LA and its doped forms at high frequencies depicts the enhanced optical quality and efficiency and hence is a very much suitable parameter in view of the second harmonic generation coefficient. UV-Vis investigation reports high transparency of LA crystals in UV region. Doping with other materials as given above further causes enhancement in the transparency ratio. An enhancement in the value of SHG efficiency is seen in case of LA single crystals (in doped form) as compared to LA single crystals (in pure form having SHG efficiency 0.33 times of KDP used as reference material) except for L-Alanine cadmium chloride enhancing its suitability to be used in NLO applications. In this review paper, we have also discussed the comments proposed by some of researchers on the novel formation of new NLO materials as L-Alanine compounds by chemically reacting L-Alanine with other materials viz., cadmium bromide, C₆H₃N₃O₇ (picric acid) etc.

L-Alanine, Amino Acids, XRD, UV-Vis