The values of optical deformation potentials (D u and D d ) for PbSe and PbTe are analyzed using absorption, luminescence and x-ray diffraction data on high quality, deep quantum well PbSe/ PbSrSe and PbTe/ PbEuTe structures. Published optical data on PbTe/ BaF 2 structures were also used. It is important for these evaluations to use the value of isotropic deformation potential ͑D iso ͒ which is determined from the low temperature hydrostatic pressure experiments and the intervalley splitting which was determined from differential absorption spectroscopy. The fitting procedure was done using an accurate k · p model for the band structure near the fundamental gap including anisotropy, multivalley, and band nonparabolicity effects. Photoluminescence was measured in pulsed mode at 4 and 77 K, which gives the lowest energy state in the rectangular well. The strain and well parameters were measured with a high resolution x-ray diffractometer. We find the new optical deformation potential values at low temperatures: D u = −0.2 and −0.5 eV, and D d = 5.3 and 3.5 eV for PbSe and PbTe, respectively.

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A laser spectrometer for the investigation of a nonequilibrium molecular plasma was constructed. Diode lasers with a record width of a continuous frequency tuning range ( £ 10 cm" 1 ) were used in this spectrometer. The spectrometer response time (510 nsec) made it possible to use liquid nitrogen to cool the diode lasers so that the resolution was at least 10~3 cm" 1 when the tuning rate was ~ 10 5 cm" Vsec. An investigation was made of the distribution of the vibrational and rotational energies between the internal degrees of freedom of the CO 2 molecules and the gas temperature in a glow discharge was determined.