by admin | Jun 4, 2015 | sem1
Semiconductor lasers Semiconductor lasers or laser diodes play an important part in our everyday lives by providing cheap and compact-size lasers. They consist of complex multi-layer structures requiring nanometer scale accuracy and an elaborate design. Their...
by admin | Jun 4, 2015 | sem1
CO2 laser The carbon dioxide laser (CO2 laser) was one of the earliest gas lasers to be developed (invented by Kumar Patel of Bell Labs in 1964), and is still one of the most useful. Carbon dioxide lasers are the highest-power continuous wave lasers that are currently...
by admin | Jun 4, 2015 | sem1
Sonogram A sonogram is a medical procedure that uses ultrasound waves to create a picture of something that is happening within a person’s body. This is a very common procedure in pregnancy, and is what produces the black-and-white fetal pictures that so many new...
by admin | Jun 4, 2015 | sem1
Youngs modulus by uniform bending Young’s modulus is named after Thomas Young,19th century ,British scientist. In solid mechanics, Young’s modulus is defines as the ratio of the longitudinal stress over longitudinal strain, in the range of elasticity the Hook’s law...
by admin | Jun 3, 2015 | sem1
Population Inversion In science, specifically statistical mechanics, a population inversion occurs while a system (such as a group of atoms or molecules) exists in a state with more members in an excited state than in lower energy states. It is called an...
by admin | Jun 3, 2015 | sem1
Spontaneous and stimulated emission Spontaneous emission If a collection of atoms are in the excited state, spontaneous decay events to the ground state will occur at a rate proportional to N2, the number of atoms in the excited state. The energy difference between...
