We report recent results from our work on the fabrication of neodymium waveguide lasers. Several neodymium doped glasses. APG-1, LG-680, BK 7 and S 3 made by Schott Glass Technologies, Inc. were studied as candidates for use as waveguide lasers. It was found that S 3, a standard ophthalmic glass, had the best ion-exchange properties of any of the glasses studied. A waveguide laser was successfully made using the neodymium doped S 3 glass.
Polarization dependent integrated optical devices are becoming increasingly important in order to control polarization for coherent optical detection schemes, gyros, bidirectional communications using optical circulators, electro-optical switching and electro-optical phase modulation. Typically, integrated optical components are made by titanium diffusion into LiNbO3, ion-exchange or electric field assisted ion diffusion in glasses. The diffused ion concentrations determine the waveguide properties. Theloped to understand the physical limitations of these devices, and the necessary electrical characteristics that the KD*P modulators must have for use in the MSFC polarimeter. imaging systems. A near infra-red imaging polarimeter is used to measure the cubes. measurement using a known Stokes source. We discuss our work implementing computer-aided polarimetry using the Mueller calculus and applius to design waveguide structures for polarization integrated optical devices.
Low loss sol-gel derived polyceram optical waveguides have been prepared for the first time. Polyceram films were obtained by reacting (N-triethoxysilyl propyl) o-polyethylene oxide urethane with silicon and titanium alkoxides. The optical properties of the films were investigated using ellipsometry, UV-VIS transmission spectroscopy and waveguide loss measurements. Refractive index and attenuation loss measurements were carried out as a function of organic/inorganic content, different processing conditions and aging of solutions. Refractive indices as high as 1.685 and attenuation losses as low as 1.4 dB/cm were obtained. In addition, surface morphology, mechanical properties and thermal stability of the polyceram films were studied.
A series of sol-gel derived PT-based films, including PT, PZ, PZT, PLT, PLZ and PLZT, was prepared on platinized Si, fused SiO2 and Corning 7059 substrates. These films were fired at 400 - 700 C for 30 mins. The phase assembly and development were dependent on the precursor chemistries, processing and choice of substrates. The presence of Zr impacted significantly on the crystallization behavior, PbO loss and cracking behavior of the films. Crystallization was severely retarded, especially in Zr-containing PZT films when deposited on amorphous substrates compared to crystalline Pt substrates. Amorphous and crystalline PZT films can be utilized for passive and active optical applications. Waveguiding was achieved in an amorphous PZT 53/47 and a crystalline PLT 28 films and gave attenuation losses of 1.0 and 1.4 dB/cm respectively which represent the lowest values reported to date. The optical properties of the films were investigated using ellipsometry, UV-VIS transmission spectroscopy and waveguide loss measurements. Depending on composition and processing conditions, PZT films (2500 A thick) with refractive indices of 1.60 to 2.33 and absorption edges of 2900 - 3100 A can be obtained. It was ascertained that the resulting interfacial reaction layers between the films and substrates affected considerably the optical properties of thinner films (< 2000 A).
Strip-loading is a convenient and effective method to design and fabricate channel waveguides in multilayer active polymer
structures. Several micron wide strip-loaded poly(4-BCMU) waveguides are observed to be single mode at 1.06 im and
Based on the optical nonlinearity for poly(4-BCMU) measured by THG at 1.32 pm, an intensity of 650 MW/cm2 is
required to satisfy the optical phase shift material figure of merit, 4ir, for a directional coupler with 1 cm interaction
length. To estimate the optical power for directional coupler operation, we initially assume no index saturation effects,
negligible one or two photon absorption, waveguide propagation losses less than 1 dB/cm, and unity coupling efficiency.
40 W is the lowest estimated peak pulse power of operation for a device with 6 .tm2 area waveguides. Actual coupling
efficiencies of light incident on our 6 pj2 ea waveguides are between 30 % and 40 %. The propagation losses for our
sixip-Ioaded waveguides are between 4 dB/cm (i'M) and 9dB/cm (TE). The guided wave intensities are at least ten fold
lower than the input intensities. Incident peak pulse powers of at least several hundred watts will be required for 1 cm
long (lirectional coupler device operation. Initial interferometry results suggest that average power dependent thermal
phase shifts dominate peak power dependent electronic phase shifts at duty cycles approaching unity. Polymer
superlattices are considered as advanced nonlinear optical materials.
We report on the optical characterization of poly-4BCMU slab waveguides, and on the fabrication of efficient
grating guided-wave couplers using this material. Thin film samples were obtained, by spin coating,
from a cyclopentanone solution. Grating couplers were used to measure the film refractive indices and
thicknesses. Waveguide attenuation was obtained from measurements of the variation in scattering with propagation
distance in the visible and near infrared. These parameters allowed us to design, fabricate and test a
grating coupler with a coupling efficiency of 45% at 1 .064 pm.