The optical limiting properties of a one-dimensional, transparent metallodielectric photonic band gap structure are studied. Due to light confinement in the structure that enhances the nonlinear response of the layers, a nonlinear transmission dependence on the incident light intensity is found. Experimental results are reported for a four period sample where the single period consists of ZnO and Ag layers 109 and 17 nm thick, respectively. The structure was designed to exhibit a transmission resonance at 532 nm. Under the action of a Q-switched frequency doubled Nd:yttrium–aluminum–garnet laser, a decrease in transmission of approximately 50% is obtained for a maximum incident light intensity of $\text{2\hspace{0.5em}}{\mathrm{GW/cm}}^2.$ These results are explained in terms of a dynamic change of the absorption coefficient due to the enhancement of the two-photon absorption process. These results suggest that the structure is suitable for optical limiting applications in the visible range.

An extension of the second quantization scheme based on the quasinormal-modes theory to one-dimensional photonic band gap (PBG) structures is discussed. Such structures, treated as double open optical cavities, are studied as part of a compound closed system including the electromagnetic radiative external bath. The electromagnetic field inside the photonic crystal is successfully represented by a new class of modes called quasinormal modes. Starting from this representation we introduce the Feynman’s propagator to calculate the decay rate of a dipole inside a PBG structure, related to the density of modes, in the presence of the vacuum fluctuations outside the one-dimensional cavity.

The spectral transmission properties of a self-similar corrugated optical waveguide are studied theoretically. The structure can be realized by square-wave modulation of the guiding layer thickness of a planar waveguide such that the thickest layers belong to a triadic Cantor set. The transmission spectrum exhibits localized peaks inside forbidden frequency band gaps. This feature could be useful in the design of novel filters. Moreover, the self-similarity of the structure is reflected in the weak self-similarity of the transmission spectrum.

Field-dependent phase shift and conversion efficiency of parametric processes in quadratic lossless nonlinear media are studied as a function of phase mismatch and of input field amplitude.

The mirror temperature response of a diode laser to injection current is studied through the photodeflection method. A theoretical model is presented together with some experimental measurements. Theoretical results are compared with experimental measurements for an AlGaAs quantum well laser diode.

A new method based on the photothermal deflection technique is described to determine the mirror temperature of a semiconductor laser diode as a function of intensity of drive current. The device’s effective thermal diffusivity can also be measured. A short theoretical discussion is presented together with experimental measurements performed on three different kinds of laser diodes.