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The applicably of multi-objective optimization to ellipsometric data analysis is presented and a method to handle complex ellipsometric problems such as multi sample or multi angle analysis using multi-objective optimization is described. The performance of a multi-objective genetic algorithm (MOGA) is tested against a single objective common genetic(More)
We present a two-state practical quantum bit commitment protocol. For an optical realization of the protocol, we model the errors, which occur due to the noise and equipment (source, fibers and detectors) imperfections, accumulated during emission, transmission and measurement of photons. The optical part is modeled as a combination of a depolarizing(More)
In this work we proposed a relative humidity (RH) sensor based on a Bragg grating written in an optical fiber, associated with a coating of organo-silica hybrid material prepared by the sol-gel method. The organo-silica-based coating has a strong adhesion to the optical fiber and its expansion is reversibly affected by the change in the RH values(More)
In this paper we summarize the research activities at the Instituto de Telecomunicações--Pólo de Aveiro and University of Aveiro, in the field of fiber Bragg grating based sensors and their applications in dynamic measurements for Structural Health Monitoring of slender structures such as towers. In this work we describe the implementation of an optical(More)
All-optical flip-flops are key elements in photonics switching techniques, which justify the continuous interest to develop new solutions for high-speed and low-power one-bit memories. In this paper, a novel scheme for all-optical clocked D flip-flop based on a single Mach-Zehnder interferometer, with semiconductor optical amplifiers in both arms (SOA-MZI),(More)
In this work, we have presented a simple approach to design a multichannel sampled fiber Bragg grating (SFBG) for dispersion compensation, based on groups of SFBG with phase modulation between groups. We present also an apodization technique that minimizes the high group delay ripple that occurs with this approach. To demonstrate an application, was made a(More)
In this work is presented a technique to measure the optical signal to noise ratio (OSNR) of a channel, based on a high birefringent fiber Bragg grating (HiBi FBG). The HiBI FBG reflects at two different spectral bands, these bands are related with the effective refractive indexes for the optical field components along the two optical axis of the HiBi(More)