“…These crystals can combine the infrared laser emission of neodymium or ytterbium with the second-harmonic generation (SHG) property of the hosts to produce visible laser radiation by SFD, leading to simple, compact and robust devices. As a consequence, besides the well-known nonlinear optical crystals of YAl 3 (BO 3 ) 4 [4,5] and YCa 4 O(BO 3 ) 3 [6] series, numerous crystals such as La 2 CaB 10 O 19 [7], Na 3 La 9 O 3 (BO 3 ) 8 [8], BiB 3 O 8 [9], BaCaBO 3 F [10,11] and YCa 9 (VO 4 ) 7 [12], have been exploited and investigated extensively.…”