A ruby crystal rod operates as an amplifier for the radiation at λ! = 694.3 nm that coincides with the central wavelength of the rubyâs atomic transition. The quantum efficiency of the transition is close to 100 %, the spontaneous emission lifetime is t!" = 4.3 ms, and the transition cross section at the central wavelength is ð(λ!) = 2.5 x 10!!" cm!.
a) Assuming a homogeneously broadened Lorentzian transition lineshape, calculate the transition bandwidth Îv (FWHM).

Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg.k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m.k