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A novel method is presented for measurement of the rise in temperature and thermal rise time of a semiconductor laser diode (LD) under pulsed operation. The technique employs the shift in LD threshold current which occurs with a rise in junction temperature. Practical results are given, showing a rise time of about 10 ns.

Poly(vinylidene fluoride) (PVDF) films filled with BiCl 3 in the mass fraction range of 0.1 W 10 were prepared. a-and b-Crystalline PVDF phases were detected and characterized by spectroscopic analysis. Fourier transform infrared analysis detected the presence of a-and bphase head-to-head and tail-to-tail polymer chain defects. The band detected at 1670 cm À1 was assigned to C¼ ¼C, indicating polarons in the polymeric matrix. The degree of crystallinity increased by increasing the filling level (FL), and the maximum relative b-phase content was found at w ¼ 5% FL. This result was confirmed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis. The Xray analysis confirmed the presence of a and b phases, and no peaks corresponding to pure BiCl 3 were found. DSC therograms showed a sharp endothermic peak at T 1 ¼ 444 K for different FLs because of the melting. This peak was used to calculate the activation energy and the order of the reaction. The DC electrical resistivity was attributed to the onedimensional interpolaron hopping mechanism. The FL dependence of log r and hopping distance (R o ) at 373 K was observed, indicating the FL affected the distribution of the hopping sites.

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