1. Material Research LaboratoryNational Institute of Technology CalicutKozhikodeKerala673601India
2. Department of PhysicsVTM NSS CollegeDhanuvachapuramThiruvananthapuramKerala695503India
3. Laser and Nonlinear Optics LaboratoryNational Institute of Technology CalicutKozhikodeKerala673601India