Department of Applied Physics & Optoelectronics, Shri G. S. Institute of Technology & Science, Indore 452 003 MP India \affiliationDepartment of Applied Physics & Optoelectronics, Shri G. S. Institute of Technology & Science, Indore 452 003 MP India \email[email protected] \affiliationSchool of Physics, Laser Bhawan, Devi Ahilya University, Indore 452 017 MP India