Enhancement of nonvolatile holographic storage properties in In:Ce:Mn:LiNbO3 crystal by [Li]/[Nb] ratios

• In:Ce:Mn:LiNbO3 crystals were grown with various [Li]/[Nb] ratios.
• Distribution coefficients of In3+ decreases with increase [Li]/[Nb] ratios in the melts.
• Holographic response time and photorefractive sensitivity of In:Ce:Mn:LiNbO3 with the ratios of [Li]/[Nb] 1.38 are improved considerably.

In:Ce:Mn:LiNbO3 crystals were grown by Czochralski technique with various [Li]/[Nb] ratios of 0.946, 1.05, 1.20, 1.38 in the melt. The infrared (IR) spectrum and inductively coupled plasma–atomic emission spectroscopy (ICP–AES) were used to investigate defect structure of these crystals. The nonvolatile holographic storage properties of In:Ce:Mn:LiNbO3 crystals were studied with the two-wave mixing technique. The grating was recorded by a Kr+ laser (476 nm) and read by a He–Ne laser (633 nm). Experimental results indicated In:Ce:Mn:LiNbO3 crystals with the [Li]/[Nb] ratios of 1.38 has the shortest access times of 310 s and the highest photorefractive sensitivity of 3.23 mm/J.