Photonic Materials Technology Section (PMTS)

Photonic & Detector Materials Laboratory (PDML)

X-ray diffraction topography is used for characterizing defects state of the crystal. In particular, the following defects can be visualized:

It is based on Bragg’s law, 2d_hkl sin⁡θ=nλ. Defects result in lattice misorientations (δθ), which is maximum in the vicinity of the defect and zero sufficiently away from it. These misoriented lattice planes do not satisfy the Braggs Law which leads to low diffracted intensities and hence image with varying degree of contrast is imaged.

X-ray topogrpahic images of crystalline sample [Cryst Eng Comm 15 (2013) 9955; RRCAT Newsletter 26 (2) (2013) 26; Opt. Mater. 46 (2015) 329]

The crystalline quality and optical homogeneity of the grown crystals was assessed using conoscopy, birefringence interferometry and high resolution XRD technique. [Cryst. Res. Technol., 43 (4) (2008) 438-442; Cryst. Growth Des., 8 (12) (2008) 4424-4427; Cryst. Res. Technol., 44 (3) (2009) 305-308; Physica-B 404 (20) (2009) 3507-3509; Cryst. Res. Technol. 44 (12) (2009) 1303-1307]

Two-wave coupling set up for optical data storage properties of photorefractive crystals

Diffraction efficiency of Fe:LN as a function of annealing and proton exchange processes [Physica B 404 (2009) 3507-3509]

Optical data storage properties of Fe:LN and FeMn:LN congruent lithium niobate crystals [Proc. PHOTONICS-2008, IIT Delhi; Proc. NLS-19 (2010), RRCAT Indore]

Two wave coupling set up for quantifying photorefractive properties of polymer composites [Proc. NLS-28 (2020), VIT Chennai]