- Lasers or based on stimulated emission which are done with the help of population inversion through pumping phenomenon.
- Population inversion is the process in which the population of charge careers in higher meta stable state is increased as compared to lower stable state through pumping phenomenon. Hence, excited particles are broad to some energy level, hence, they will emit out light of near by wavelength. Hence, The Spectral width is narrow So, LASER’s are considered as Monochromatic Coherent source of light. So, Chromatic dispersion is low hence, LASER supports high data rate and long distance communication.
- Due to stimulated emission LASER’s are directional and have high coupling efficiency. Hence, preferred for Single mode fiber.
- NOTE 1:- LASER‘s are not thermally stable hence, optical feedback is required for stability which makes the circuit costly and complex.
- NOTE 2:- Due to Thermal instability the life spam of LASER’s is less.
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