A method of providing asymmetric feedback in the triangular ring laser structure was devised through the simple alterations of the waveguide shape. Two kinds of alterations were designed and implemented, one being the “optical diode,” the other being the tapered waveguide. Unidirectional operation was achieved for the ring lasers, with a single-beam slope efficiency of 0.23 W/A, which was the highest single-beam slope efficiency reported for semiconductor ring lasers.

The electro-optic properties of polymer films are measured by an original technique whereby a periodic sequence of poling and probing steps permits alternation of the application of orientation and dephasing potentials. Relaxation dynamics of the electro-optic coefficient of Red–Acid–Magly crosslinkable polymer films is studied as a function of the temperature of the samples. The time constant of the decay τ as measured at several temperatures is found to follow a Vogel–Fulcher–Tamann—Hesse dependence, for temperatures above glass transition. Poling the samples in the presence of a pulsed electric field leads to a r33 electro-optic coefficient as high as 6 pm/V.

We report measurements on the isothermal relaxation dynamics of the electro‐optic coefficient of electric field poled polymeric films. The studied copolymer is a side‐chain Disperse Red 1/poly–methyl–metacrylate combination. The isothermal relaxation is shown to follow a Kohlrausch–Williams–Watts stretched exponential dependence, whose parameters are strongly dependent on temperature. The average decay constant is shown to follow an Arrhenius temperature dependence below the glass transition Tg, while it is described by a Vogel–Fulcher–Tamann–Hesse above Tg. The values of the decay constant confirm a much better stability of the polymer orientation with respect to guest‐host systems. The relaxation is shown to be due to a broad distribution of relaxation rates, the width of which can be qualitatively described by an empirical relation, which has already been used for guest‐host systems. The measurement technique permits monitoring relaxation in a standard dielectric relaxation configuration and performing unconventional poling of the samples

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Crosslinking of polymers with dipoles can be followed by means of dielectric, pyroelectric, and in situ electro-optic measurements. All three techniques provide similar insights as to the cross-linking process. In addition, electro-optic measurements allow for the determination of the resulting optical nonlinearity. After crosslinking is completed the polymer behaves like a side-chain polymer. In addition, photoinduced poling of an already cross-linked dipolar polymer network is demonstrated