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A screening method is reported for electro-optic (EO) polymers with an emphasis on broadband device suitability. The method is based on comparing the signal from second harmonic generation (SHG) and the leak through current (LTC) during poling. Plots of the SHG and LTC are used to define high EO activity-low current poling windows that are critical for low driving voltage, broadband devices with relatively low optical loss. The screening procedure was used to select an EO polymer core that resulted in a 40Gbits∕s broadband modulator with a driving voltage of 1.3V and an insertion loss of <8dB.

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The optical properties such as index of refraction and optical absorption of many chromophore-containing polymers are sensitive to the physical and chemical environment to which the polymers are exposed. To demonstrate such applications, chemical sensors to detect trace explosives are presented. The sensors use polymers that contain chromophores whose molecular structure consists of an electron donor and an electron acceptor connected by a charge-transfer bridge of conjugated π-orbital electrons. The polymers used for the trace explosives sensor are not poled, and the chromophores are randomly oriented in the polymer host. Waveguide microring resonator and fiber Bragg grating structures were used in these sensors to enhance the detection sensitivity. Because chromophores undergo photodecomposition under intense ultraviolet radiation, chromophore-containing polymers can be patterned with ultraviolet light to create optical resonator structures in a single photobleaching step. The chemical sensor has shown part-per-billion level sensitivity and good specificity to the vapor, in air, of an explosive simulant 2,4-dinitrotoluene. † Part of the "Larry Dalton Festschrift".