Chapter 11, Problem 38P

A three level laser system emits a wavelength of 550 nm. What will be the ratio ofpopulation of upper level (N2) to lower level (N1) if the pumping mechanism is shut off(assume room temperature is 300 K). At what temperature one can achieve thepopulation ratio of ½ in this laser (K = 1.38 × 10-23 JK-1).

Calculate (a) the thermal wavelength, (b) the translational partition function of an Ar atom in a cubic box of side 1.00 cm at (i) 300 K and (ii) 3000 K.

a. Is a 4p → 4s transition allowed in sodium? If so, what is its wavelength? If not, why not?b. Is a 3d → 4s transition allowed in sodium? If so, what is its wavelength? If not, why not?

Say that the surface of a star has a temperature of 6000 K and an electron density of n = 2.6 x 1019 electrons per m3. Using the Saha equation, what fraction of hydrogen atoms is ionized?

The active volume of a laser constructed of the semiconductor GaAlAs is only 200 mm3 (smaller than a grain of sand), and yet the laser can continuously deliver 5.0 mW of power at a wavelength of 0.80 mm.At what rate does it generate photons?

A 10 monolayers thick layer of Ag is deposited on Mo. The intensity of electrons emitted by the Ag and Mo can be measured separately. The ratio IAg/IMoi =100 for the deposited film. The mean free path of the electrons is 0.6 nm and the thickness of one layer is 0.18 nm. After heating the sample, the Ag layer has agglomerated in islands that cover a fraction q of the surface. Between the islands the Mo is “visible”. The intensity ratio after agglomeration is IAg/IMof = 1. Calculate the sensitivity of the electron spectroscopy technique for Ag with respect to Mo. I.e. how many electrons are emitted from one layer of Ag atoms compared to one layer of Mo atoms. And use this to determine what fraction of the surface is covered by islands?

At a certain temperature, the electron and hole mobilities in intrinsic germanium are given as 0.43 and 0.21 m2/V s, respectively. If the electron and hole concentrations are both 2.3 x 10'® m, find the conductivity at this temperature.

What is the Doppler-broadened linewidth of the electronic transition at 821 nm in atomic hydrogen at 300 K?