A) draw energy level diagrams for three and four level discrete energy laser systems and explain how population inversion is obtained. which system is likely to have the lower lasing threshold and why? [5 9r b) derive the two rate equations for the upper and lower energy levels of a four level system. assume that the only physical mechanisms of interest are stimulated emission, spontaneous emission, stimulated absorption and optical pumping. [4] 10-9 9 c) sketch the relationship between (i) population inversion and (i) optical output power with pumping rate. [4] d) consider a he-ne laser operating at a wavelength of 632.8nm with a mirror separation of 0.40m and mirror reflectivities of 95% and 100%. assuming the loss coefficient is 0.05m, calculate the threshold gain coefficient of the laser. 12] d) the threshold gain of a laser is 1.1m1. given that the mirror reflectivity is 0.8 and the device length is 0.5m, determine the scattering loss.
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Physics, 22.06.2019 08:30
Pl asaaap ! match the term to the correct description. a type of wave that transfers energy where the particles in the medium move perpendicular to the direction in which the energy is traveling. a type of wave that transfers energy where the particles in the medium move parallel to the direction in which the energy is traveling. movement that is back and forth, like an equal sign = a type of wave that transfers energy where the particles in the medium move in a circle motion while the energy travels left or right. movement that is like a t transfers energy from one location to another 1. wave 2. parallel movement 3. perpendicular movement 4. transverse wave 5. longitudinal wave 6. surface wave
Answers: 1
Physics, 22.06.2019 11:00
A2.00-m long piano wire with a mass per unit length of 12.0 g/m is under a tension of 8.00 kn. what is the frequency of the fundamental mode of vibration of this wire?
Answers: 3
Physics, 22.06.2019 12:20
A2.0 μf capacitor and a 4.0 μf capacitor are connected in series across a 0.827-kv potential. the charged capacitors are then disconnected from the source and connected to each other with terminals of like sign together. find the voltage across each capacitor.
Answers: 2
Physics, 22.06.2019 16:50
Aresistor with an unknown resistance is connected in parallel to a 9 ω resistor. when both resistors are connected in parallel to an emf source of 21 v, the current through the unknown resistor is measured with an ammeter to be 4 a. what is the resistance of the unknown resistor? answer in units of ω.
Answers: 3
A) draw energy level diagrams for three and four level discrete energy laser systems and explain how...
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