In recent years, there has been tremendous development in the fabrication of suitable materials for optoelectronic, laser, photovoltaic devices, acousto-optic, sonar and infrared detectors applications. Mastering in synthesis, growth and characterization is an essential requirement for fully realizing the potential applications of the materials technology for the construction of novel devices for Laser, microwave, optoelectronic and other applications. The anisotropy in the crystals gives them enhanced properties as required in the field of non-linear optics. With the advent of laser sources, a nonlinear optical phenomenon has got tremendous interest and nonlinear optical (NLO) materials play a key role in the development of laser technology. Because of the variety and complexity of the material systems involved, several approaches towards synthesis, growth and characterization have been developed during the past decades. Laser materials can be classified into Inorganic, Organic and Semi organic categories. Urea, DAST, mNA, POM, NPP, MAP are examples of organic family crystals where as L-Arginine phosphate (LAP), Zinc tris thiourea sulphate (ZTS), BTCC, ZCTC belongs to semi organic class. Inorganic NLO crystals are Potassium titanyl phosphate (KTP), GdYCOB, KAB, Beta Barium Borate (BBO), LBO, KDP and LiNbO3. Synthesis and characterization of technologically important Borate based materials for NLO applications will be reviewed. The raising demand for UV lasers has led to the development of various NLO materials. A series of borate materials – Rare earth calcium oxy borate (RECOB) with the general chemical formula RECa4O(BO3)3 with RE=Y,Gd, Nd, Sm, etc. are reported to be synthesized from their repective melts. The RECOB crystals are excellent NLO materials and when doped with `laser-active' ions (Nd3+, Yb3+), they become efficient laser-host crystals. The single crystals of YCOB were grown by flux technique using boron-tri-oxide as a flux. This technique enables to grow YCOB crystals below its melting point (1510°C) . Powder XRD studies were carried out on both the polycrystalline and single crystals of YCOB using the CuKα X-rays (λ = 540 Å) at a scan rate of 0.05°/ min. The formation of YCOB was confirmed in both the samples. The powder XRD pattern of the grown crystals reveals the formation pure YCOB single phase. There are no excess peaks due to impurities or flux incorporations. UV-VIS-NIR studies were carried out on the as-grown crystals of YCOB which indicates that YCOB crystals have a sharp cut-off around 220 nm and the crystal is highly transparent (>75%) from 220 – 1100 nm. The high transparent nature of the crystals from the deep UV region enables it to be an excellent NLO material for UV applications. The results obtained suggest that flux technique is an excellent method to grow YCOB crystals. Crystal growth and characterization of novel borate materials like XAl3(BO3)4 where X = Nd, Yb and Er will be reviewed in detail.