Search

Metal-slotted optical waveguides (MSOWs) using an electro-optic polymer material have been experimentally demonstrated. The device consists of a three-layered slab waveguide in that the thin metal (gold) film strips are embedded on top of the lower cladding. The optical mode shapes and effective index of the propagation modes of the proposed waveguide structure were calculated using a simplified effective index method and a simulation tool. The fabrication and the device characteristics of a variable optical attenuator and an optical phase modulator based on MSOWs are discussed. [ABSTRACT FROM AUTHOR]

Electro-optic (EO) polymer modulators with a wide range of thermal stability from -46 °C to 95 °C for fiber-optic gyroscope applications are reported. The synthesized EO side-chain polymer used has a glass transient temperature (Tg) of 200 °C and a large EO coefficient of 25.2 pm/V in a real device measurement. Mach–Zehnder (MZ) intensity and optical phase modulators are implemented based on this high-Tg side-chain EO polymer, exhibiting ∼3.75 V half-wave voltage with 1.5 cm interaction length and 2.3 cm total length at 1.55 μm wavelength. The optical fiber-to-lens insertion loss is ∼7.5 dB in the MZ interferometers and ∼6 dB in the straight waveguides. We examine the long-term thermal stability of these devices and demonstrate their ability to meet the strict requirements of various EO device applications, particularly fiber-optic gyroscopes. [ABSTRACT FROM AUTHOR]

We demonstrate metal-defined electro-optic polymer phase modulators for the first time. A metal strip patterned on top of a three-layer slab waveguide causes a strain-induced refractive index change, resulting in lateral optical mode confinement within the core layer. The strain profile, refractive indexes, and optical mode shapes of the metal defined optical waveguide are obtained analytically. Electro-optic phase modulators fabricated using this technique have a driving voltage of 5.6 V, and ∼18 dB of extinction ratio at 1.55 μm wavelength. These results may be used in the complex design of integrated polymer optical circuits that require a simple and cheap fabrication process. [ABSTRACT FROM AUTHOR]

Multiple quantum well structures consisting of alternating layers of two crystalline organic semiconductors, namely, 3,4,9,10 perylenetetracarboxylic dianhydride (PTCDA) and 3,4,7,8 naphthalenetetracarboxylic dianhydride (NTCDA), have been grown by organic molecular beam deposition. The individual layer thicknesses in the multilayer samples were varied from 10 to 200 Å. X-ray diffraction and birefringence data show that there is a strong structural ordering in all layers, as well as across large spatial distances along the sample surface. Thus, the growth is ‘‘quasi-epitaxial’’ even though the PTCDA and NTCDA crystal structures are incommensurate. From the optical absorption spectra, it was found that the lowest energy PTCDA singlet exciton line shifts to higher energy with decreasing layer thickness. Comparison of these results with a quantum mechanical model based on exciton confinement in the PTCDA layers is proposed to describe the energy shift. [ABSTRACT FROM AUTHOR]