Large size single crystals of potassium L-ascorbate monohydrate, KC 6 H 7 O 6 .H 2 O (KLAM), are grown using solution growth technique by lowering the temperature at the rate of 0.24 °C/h, where water was used as a solvent. The structure of KLAM was solved by single-crystal XRD. KLAM crystallizes in P 2 1 space group with unit cell parameters a = 7.030(5)Å, b = 8.811(5)Å, c = 7.638(5)Å and β = 114.891(5)°. The crystal grows with bulky morphology in all three directions having (100), ( $$\stackrel{-}{1}$$ 1 - 00), ( $$\stackrel{-}{1}$$ 1 - 10), (0 $$\stackrel{-}{1}$$ 1 - $$\stackrel{-}{1}$$ 1 - ), (0 $$\stackrel{-}{1}$$ 1 - 1), (001) and (00 $$\stackrel{-}{1}$$ 1 - ) prominent faces. Thermo-gravimetric analysis and Differential scanning calorimetry measurements show that KLAM is stable up to 80 °C. The crystal offers good optical transparency with a lower cut off as low as 297 nm. Second harmonic conversion efficiency measured on powder sample is 3.5 times that of potassium dihydrogen phosphate. Phase matching (PM) is observed on the a -plate of the KLAM. Noncollinear phase matching rings are also observed near the PM directions, which help to identify the PM directions. The observation of noncollinear second-harmonic rings up to third-order indicates high magnitudes of nonlinear optical coefficients. Single-pulse laser damage threshold value of the crystal is 3.07 GW/cm 2 at 1064 nm on the a -plate of the crystal.

中文翻译：

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L-抗坏血酸钾一水合物：一种新型金属有机非线性光学晶体

L-抗坏血酸钾一水合物 KC 6 H 7 O 6 .H 2 O (KLAM) 的大尺寸单晶使用溶液生长技术通过以 0.24 °C/h 的速率降低温度来生长，其中水用作一种溶剂。KLAM的结构通过单晶XRD解析。KLAM 在 P 2 1 空间群中结晶，晶胞参数 a = 7.030(5)Å、b = 8.811(5)Å、c = 7.638(5)Å 和 β = 114.891(5)°。晶体在具有 (100)、( $$\stackrel{-}{1}$$ 1 - 00)、( $$\stackrel{-}{1}$$ 1 - 10) 的所有三个方向上以体积大的形态生长, (0 $$\stackrel{-}{1}$$ 1 - $$\stackrel{-}{1}$$ 1 - ), (0 $$\stackrel{-}{1}$$ 1 - 1 )、(001) 和 (00 $$\stackrel{-}{1}$$ 1 - ) 突出的面孔。热重分析和差示扫描量热法测量表明 KLAM 在高达 80 °C 时是稳定的。该晶体具有良好的光学透明度，截止波长低至 297 nm。在粉末样品上测得的二次谐波转换效率是磷酸二氢钾的 3.5 倍。在 KLAM 的 a 板上观察到相位匹配 (PM)。在 PM 方向附近也观察到非共线相位匹配环，这有助于识别 PM 方向。对高达三阶的非共线二次谐波环的观察表明非线性光学系数的量级很高。在晶体的a板上，晶体的单脉冲激光损伤阈值在1064 nm处为3.07 GW/cm 2 。在 PM 方向附近也观察到非共线相位匹配环，这有助于识别 PM 方向。对高达三阶的非共线二次谐波环的观察表明非线性光学系数的量级很高。在晶体的a板上，晶体的单脉冲激光损伤阈值为1064 nm处的3.07 GW/cm 2 。在 PM 方向附近也观察到非共线相位匹配环，这有助于识别 PM 方向。对高达三阶的非共线二次谐波环的观察表明非线性光学系数的量级很高。在晶体的a板上，晶体的单脉冲激光损伤阈值在1064 nm处为3.07 GW/cm 2 。