Abstract: The invention relates to an optically pumped multilayered modulator having surface-normal geometry. The multilayer structure comprises an absorber section through which an optical signal (401) to be modulated is coupled from an input (401) to an output (400). The multilayer structure further comprises control means for supplying a control signal for controlling the transmission characteristics of the absorber section. The control signal is generated by an in-plane waveguide-type laser integrated monolithically with the saturable absorption region. The in-plane control laser includes waveguide regions (405) and multiple-quantum-well layers (409) used as a gain medium. The laser beam is adapted to travel through the absorber section in order to modulate the transmission characteristics of the absorber section.

Abstract: New fiber lasers, spontaneous emission sources, and optical fiber amplifiers are provided. Their conventional counterparts, which have a fiber doped with thulium (Tm) ions and excited by 0.67 ?m or 0.8 ?m pumping light, have a problem in that their characteristics are deteriorated with the elapse of time. The new fiber lasers, spontaneous emission sources, and optical fiber amplifiers use 1.2 ?m light as pumping light. Alternatively, they use a pumping source for exciting the thulium from the lowest energy level 3H6 to 3H5 excitation level. As a more preferable configuration, they improve the emission efficiency at 2.3 ?m band by disclosing Tm-doped host glass.

Abstract: An optical filter includes at least one waveguide structure. The optical filter also includes a plurality of optical resonators that are aligned in an coupled arrangement with the at least one waveguide structure so as to produce an asymmetric distribution of coupling coefficients.

Abstract: Optical waveguide composite materials and integrated optical subsystems with low loss connection to optical fibers, are disclosed. The waveguide material has a varying thickness and/or refractive index from one portion (816) to another (820) and can be varied in all three directions. Methods of producing the composite materials and waveguides are also disclosed.

Abstract: Molecular systems are provided for electric field activated switches, such as optical switches. The molecular system has an electric field induced band gap change that occurs via one of the following mechanisms: (1) molecular conformation change; (2) change of extended conjugation via chemical bonding change to change the band gap; or (3) molecular folding or stretching. Nanometer-scale reversible optical switches are thus provided that can be assembled easily to make a variety of optical devices, including optical displays.