[LED illuminant-based detection of trace NO2 gases].

Light-emitting diode was used as illuminant in the present paper. The light-emitting diode was chosen according to the high absorption in the range of absorption spectrum of NO2. The pollutant concentration can be calculated by measuring the absorption spectrum, and fitting the experimental absorption spectrum and normal absorption spectrum by means of least square fitting method.

[FTIR spectroscopic studies of inner stress on boron carbon nitride thin films].

Boron carbon nitride thin films were deposited by radio frequency (RF) magnetron sputtering technique using a 50 mm-diameter composite target consisting of h-BN and graphite in an Ar-N2 gas mixture. The composite target was composed of two semi disks: one of h-BN and the other one of graphite. The distance between the target and the substrate was kept at 50 mm.

[The study of infrared absorption spectrum of diamond during growth by FTIR].

The diamond thin films were deposited on silicon substrates under invariable conditions of process pressure, substrate temperature negative direct-current (dc) bias of substrate and microwave power while the rations of methane (CH4) to hydrogen (H2) changing from 3% to 5% and 9% using electron-cyclotron-resonance microwave plasma-assisted chemical vapor deposition technique (ECRCVD). In situ Fourier transform infrared spectroscopy (FTIR) have been used to study the plasma species absorbed on the substrate surfaces as well as the species above the substrates surfaces both before and during the nucleation and film growth. It is demonstrated that these techniques can provide useful information on the early stages of diamond growth.

[Study on temperature character of stimulated Raman scattering spectrum in silica fiber].

Stimulated Raman scattering (SRS) spectrum of silica fiber was studied under different temperatures. The influence of temperature on feature of SRS spectra was analyzed theoretically and experimentally. The laws of how the Raman frequency-shift, bandwidth and intensity of the first order Stokes light change with the temperature were obtained using a pulsed Q-switched doubled frequency laser.

[Ultraviolet transmission spectra of BC(x)N thin films].

BCN, BC2N and BC3N thin films with transmission increasing properties in the ultraviolet region were deposited by RF magnetron sputtering with different sputtering power (80-130 W). Fourier transform infrared absorption and X-ray photoelectron spectroscopy results suggested that the films were atomnic-level hybrids composed of B, 'C and N atoms. The compositions and transmission increasing properties of samples in the ultraviolet region were strongly influenced by sputtering power, which determined the transmission increasing properties in the ultraviolet region by changing compositions.

[Study of Raman scattering of plastic optical fiber].

The first order stimulated Raman scattering (SRS) spectrum of PMMA plastic optical fiber was given, and the characteristic of the first order Stokes spectrum was studied. The threshold and the spectrum width were measured. The formation mechanism of SRS was analyzed, and then the first order Stokes spectrum of plastic optical fiber and that of silica fiber were compared.