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Some characteristics of the reflection coefficient are considered in this paper. We study how to change the shape of the envelope reflection in the passband and consequently obtain an antireflection coating whatever the number of bases and, for a two-layer bases, the influence of the optical thickness difference on the properties of the deposit.

We report here all polycrystalline thin film solar cells of Cu2S–Zn x Cd1-x S and Cu2S–CdS prepared by solid state reaction. The efficiencies in the range of 4 to 5% have been obtained without antireflection coating. The improvement in open circuit voltage is observed in Cu2S–Zn x Cd1-x S cell with little sacrifice in short circuit current. A comparison is also made with the solar cell Zn x Cd1-x S–Cu2S prepared by spray pyrolysis and the electrical conversion efficiency about 1.0% is obtained.

The experimentally observed instability of AR-coated lasers in external cavity operation is explained by a simple theory, which yields critical values for the bias current and the reflectivities of the coated laser facet and the external mirror.

The laser damage thresholds of various types of antireflection (AR) coatings for an UV (355-nm) laser system were measured. Among them, the coatings consisting of two low-index materials, SiO2 and MgF2, had the highest average thresholds: 2.1 J/cm2 fused silica substrates and 2.6 J/cm2 sapphire substrates. The SiO2/MgF2 coating is hopeful for UV laser component.

The effect of sputtered SiO2 films as an acoustic antireflection coating for matching the large acoustic discontinuity at the sapphire/water interface is experimentally and theoretically investigated in a frequency range of 200 to 1100 MHz. By the introduction of SiO2 films, the transmission loss of more than 9 dB at the interface is reduced to less than 1 dB at a quarter-wavelength frequency of SiO2 film with high reproducibility.

Double-layer acoustic antireflection coating for the sapphire/water interface is experimentally and theoretically investigated in UHF range. By using the Au-SiO2 double layer with quarter wavelength thicknesses, the large transmission loss at the interface is almost completely reduced to be less than 0.1 dB at 600 MHz.

DFB lasers have been characterised in terms of linewidth. The effect of antireflection coating on linewidth has been measured. The frequency modulation (FM) response has been measured and the system implications of a nonflat FM behaviour are discussed. Two section DFB lasers with electro-optic tunability are described and results presented.

This paper details the error considerations in the design and construction of a two-layer antireflection coating on KCl. Methods of choosing the most appropriate design, which allows the production of a practical coating of low absorptance and reflectance, are discussed. Experimental methods of minimizing layerthickness errors are also discussed. These methods have been applied to the production of a chalcogenide glass two-layer coating consisting of Ge(30)As(17)Te(30)Se(23) and As(2)S(3). Both the reflectance and absorptance of this coating were found to be 0.02% at the design wavelength of 10.6 microm.

Operation of a double-rooftop ruby laser emitting along directions that are at an angle of 17.45° with respect to one another has been investigated. The ruby is a 3.17-cm cylinder with a 17.45° chisel at each end, one of which is silver-coated. The other end has an antireflection coating, so that external dielectric (or silver) reflectors complete two separate Fabry–Perot cavities, which have about one-third the active medium in common. A polarizer and nitrobenzene Kerr cell in each path allow fast switching from one axis of emission to the other; the switching has been accomplished within 1 μsec in the present experiment. Some implications of the experiment with regard to more general problems of laser deflection are also discussed.

In this study, Pb(Zr0.52Ti0.48)O3/BiFeO3 [PZT/BFO] multilayer thin films were fabricated using the spin-coating method on a Pt(200 nm)/Ti(10 nm)/SiO2(100 nm)/p-Si(100) substrate alternately using BFO and PZT metal alkoxide solutions. The coating-and-heating procedure was repeated several times to form the multilayer thin films. All PZT/BFO multilayer thin films show a void-free, uniform grain structure without the presence of rosette structures. The relative dielectric constant and dielectric loss of the six-coated PZT/BFO [PZT/BFO-6] thin film were approximately 405 and 0.03%, respectively. As the number of coatings increased, the remanent polarization and coercive field increased. The values for the BFO-6 multilayer thin film were 41.3 C/cm2 and 15.1 MV/cm, respectively. The leakage current density of the BFO-6 multilayer thin film at 5 V was 2.52 × 10-7 A/cm2.