Recent efforts to “engineer” new nonlinear optical materials with specific desired characteristics has engendered a need for a theoretical description of optical properties which is readily accessible to chemists, yet correctly treats the essential physics of dielectric response. This paper describes a simple empirical molecular orbital model which gives useful insights into the relationship between chemical composition, crystalline structure, and optical susceptibilities. We compare the probabilities of finding new harmonic generators in various chemical classes. Rigorous bounds on the magnitudes of linear and nonlinear optical coefficients and their anisotropies are also discussed.

Specular infrared reflectance spectra were made on hot pressed powder samples of rare earth sulfides of composition Ln2S3. The reflectance curve obtained from the Kramers-Kronig analysis is the deconvolution of the sum of the reflectance curves from the multiple grains, giving the bulk dielectric constant within the 25 cm−1 to 400 cm−1 range and transverse and longitudinal optic modes for the bulk material. Reflectance spectroscopy has shown to be a very good alternative to infrared transmission spectra in the far infrared range to obtain electro-optical information on ceramic powders.

The development of liquid crystalline mixtures with short electro-optic switching times has made possible an array of new products, including hand-held televisions and lap-top computers with flat panel displays. Whereas the switching times for materials with long switching times has been correlated with their steady shear viscosities, this is not true for materials with short switching times. Since such materials exhibit viscoelasticity in dynamic tests conducted at ultrasonic frequencies, we expect the dynamic moduli to correlate with their switching times. The viscoelastic properties of pure MBBA were measured using a piezoelectric ultrasonic composite oscillator technique. The measurement technique and the relation between the linear viscoelastic behavior and the electro-optic switching behavior will be discussed.

LiNbO3 is a relevant material to prepare a number of electrooptic (bulk and waveguide) devices. Moreover, its photorefractive (PR) behavior is also potentially useful for optoelectronic applications such as holographic storage and coherent optical amplification. For a full understanding and optimization of the PR effect, the lattice location and valence state of the active impurities is essential, since they determine the ionization and trapping capabilities for free carriers. So far, the information obtained with spectroscopic techniques (EPR, ENDOR, Mossbauer, optical) is not conclusive, except manganese and possible iron.

Rutherford backscattering spectroscopy along ion channeling directions is useful for numerous applications in the characterization of all types of materials, due to its sensitivity to interstitial location, lattice quality, and composition. The determination of channeling directions and sample orientation in materials with high symmetry lattices is usually straightforward. However, many optical materials have relatively low crystal symmetry, which complicates the determination of likely directions for ion channeling. This is especially true of electrooptic materials, such as LiNbO3, which lack inversion symmetry. Therefore, an algorithm for the calculation of likely channeling directions in low symmetry lattices has been developed.

Guided wave technology based on III–V compound semiconductor materials is important for optical signal processing, fiber communication and sensor applications. The provision of heterojunction and quantum well materials by LPE, MBE, and MOCVD have led to new concepts and techniques in tailoring the properties of discrete devices and optoelectronic integrated circuits. This paper discusses the electro-optical properties of heterojunction, quantum well, superlattice based on two novel effects, the Franz-Keldysh effect in bulk materials and the quantum confined Stark effect in semiconductor quantum wells. The electroabsorption and electrorefraction properties resulted from these effects are utilized in the realization of some waveguide modulators. Materials based on InGaAsP/InP heterojunctions, InGaAs/GaAs strained layer quantum wells and InGaAs/InP quantum wells will be emphasized.

Low optical loss (<dB/cm) thin films of Corning 7059 glass have been prepared by electron beam deposition and by rf magnetron sputtering. The effects of gas pressure, deposition power and oxygen-to-argon ratio on refractive index and optical loss were studied. Deposition rates obtained with the sputtering process were about 0.2 nm/sec while much higher deposition rates (2 nm/sec) were obtained with electron beam deposition. The films were found to be amorphous in structure. The refractive index of electron beam-deposited films was measured as 1.50 while the sputtered film index was measured as 1.525. Film composition and composition profiles determined by RBS, electron microprobe and neutron activation analysis are presented. Sputtered films show uniform elemental composition profiles for Si, Ba, B and Al. Electron beam-deposited films have uniform composition profiles if the deposition power is kept constant. The rms surface roughness of the films, measured using an optical profilometer, is 1 nm. The contributions of surface roughness and cladding layer thickness to optical loss are discussed. The major source of optical loss in sputtered films is light absorption.

Ion implantation has been used to introduce Ti at very high doses (>3 × 1017 /cm2) into the near-surface region of LiNbO3 to change the index of refraction.’ In the as-implanted state, the near surface is amorphous. Thermal annealing in water-saturated oxygen 1000°C crystallizes the amorphous region and incorporates the Ti into substitutional sites in the lattice at concentrations that exceed 10 at.%. Recrystallization takes place by solid-phase epitaxy. Both planar and channel waveguides have been fabricated with optical attenuations of <1 dB/cm. Both Mach-Zehnder and Bragg modulators have been fabricated using Ti implantation of LiNbO3. The characteristics of these devices have been determined and will be reported. The higher Ti concentrations which can be achieved by implantation allows tighter mode confinement and smaller mode profiles than with Ti-diffused guides.