a) What is LASER from an electrical materials perspective? (1 Mark) i. Distinguish between stimulated emission and spontaneous emission of laser light? (4 marks) ii. Hence explain the process of population inversion? (3 marks) iii, How is the process in (ii) signilicant in irnproving laser efliciency? (2 marks) b) What happens during the following levels in pumping schemes? i. Two-level (2 marks) ii. Three-level (2 marks) iii. Four-level (3 marks) c) Distinguish beteween Active Q-switching and Passive Q-switching as used in LASER Technologr.(2 marks) d) Explain the meghanism of operation of laser light and laser pens in medical operations?