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We propose a new, to the best of our knowledge, adaptive control method to attenuate beam jitter in image stabilization systems, which breaks the restrictions of existing adaptive control methods in terms of time consumption and control stability, and then provides an innovative way for tip-tilt disturbance rejection. In this approach, disturbance rejection could be converted to optimize error attenuation through the parameters design of the Youla-Kučera (YK) parametric controller, which are determined by a new on-line power spectrum density (PSD) estimation of tip-tilt errors to identify the frequency and amplitude of unknown disturbances. Experimental results demonstrate that the proposed method working in an adaptive correction process can attenuate the beam jitter to approximately 1/3 less than the original control error.

We demonstrate a plasmonic fiber tip for relative humidity (RH) detection by integrating a gold nanomembrane onto the end-face of a multimode optical fiber via a flexible and high-efficiency transfer method. Fast water condensation/evaporation is responsible for the high performance of the fiber tip in response to RH. A high sensitivity of 279 pm/%RH is obtained in the range of $ 11\% \sim 92\% {\rm RH} $11%∼92%RH. Taking advantage of the fast dynamics (response and recovery times of 156 ms and 277 ms), the plasmonic fiber tip offers an excellent detection capability to human breaths at varied frequencies and depths. The compact, easy-fabrication, and fast-dynamics plasmonic platform has versatile potential for practical applications, including environmental and healthcare monitoring, as well as biochemical sensing.

A general model of excitation and fluorescence recapturing by the forward and backward modes of filled microstructured optical fibers (MOFs) is presented. We also present experimental results for both backward and forward fluorescence recapturing within a MOF as a function of fiber length and demonstrate a good qualitative agreement between the numerical model and experimental results. We demonstrate higher efficiency of fluorescence recapturing into backward modes in comparison with that of forward modes.

We report a fully integrated, passive, all-optical regenerator capable of terabit per second operation, based on a highly nonlinear chalcogenide (As2S3) glass rib waveguide followed by an integrated Bragg grating bandpass filter. We demonstrate a clear nonlinear power transfer curve with 1.4 ps optical pulses, capable of improving the signal-to-noise ratio and reducing the bit error rate for digital signals.

A large phase shift of 4.7pi at 1.53 microm has been observed from a low-loss (0.2 dB/cm), small-core As2S3 waveguide fabricated by dry etching. The strength of the nonlinear response was limited by photosensitivity and photocrystallization of the As2S3 films at 1.53 microm, far below the material bandgap.