In 1953, the Hungarian-American physicist John von Neumann has given the concept of the first semiconductor laser or laser diode and in 1957 the Japanese engineer Jun-ichi Nishizawa patented the world’s first semiconductor laser. But this laser diode is very power inefficient and practically useless. Since then research has been done across laser diodes for years and today we have lasers like DFB and FP Laser which give us efficient results with low power. These laser diodes generally work on 1310nm and 1550nm wavelengths. Although there may be a slight difference in wavelengths. In this blog, we will learn about DFB and FP Laser with their structure and applications. And in the last, we see a quick comparison of both of these lasers.