M. Trejo-Duran

Self-diffracting effects in hybrid materials

The authors experimentally demonstrate self-diffraction effect in a hybrid material. Patterns at different light intensity levels were obtained. A dependence of the number of diffraction rings with the intensity of laser is observed.

Nonlinear optical characterization of ionics liquids of 1- methylpyrrolidine family

Research nonlinear optical properties of the materials for the fabrication of opto-electronic devices have growth in the last years. Ionics liquids present nonlinear optical properties. In this work we present the results of nonlinear optical properties of four ionic liquids of 1-methylpyrrolidine family, analyzed using a z-scan technique. The results show the difference obtained using or not a chooper for measuring the nonlinearity and the photoinduced lens. Ionic liquids have a negative nonlinearity (self-defocusing) of thermal origin.

Nonlinear optical characterization of ionics liquids

In this work, we show results about the nonlinear optical characterization for four ionic liquids (ILs), namely 1-buthyl-3- methylimidazolium tetrafluoroborate ([BMIM][BF4]), 1-ethyl-3-methylimidazolium Bis((trifluoromethyl)sulfonyl)imide ([EMIM][TF2N]), 1-ethyl-3-methylimidazolium trifluoroacetate ([EMIM][CF3COO]),1-buthyl-3-methylimidazolium trifluoroacetate ([BMIM][CF3COO]), using z-scan technique.

Photonic density of states maps for design of photonic crystal devices

In this work, it has been investigated whether photonic density of states maps can be applied to the design of photonic crystal-based devices. For this reason, comparison between photonic density of states maps and transmittance maps was carried out. Results of comparison show full correspondence between these characteristics. Photonic density of states maps appear to be preferable for the design of photonic crystal devices, than photonic band gap maps presented earlier and than transmittance maps shown in the paper.

Nonlocal nonlinear refraction in Hibiscus Sabdariffa with large phase shifts

In this work we present a study of nonlinear optical properties in organic materials (hibiscus sabdariffa). Our results demonstrate that the medium exhibits a highly nonlocal nonlinear response. We show preliminary numerical results of the transmittance as nonlocal response by considering, simultaneously, the nonlinear absorption and refraction in media. Numerical results are accord to measurement obtained by Z- scan technique where we observe large phase shifts. We also analyze the far field diffraction ring patterns of the sample.

PC-Based systems for experiments in optical characterization of materials

An automatic control for applications of optical characterization of materials using the optical Z-Scan technique is presented in this work. The emphasis is placed in the design of the graphical user interface (GUI) and the automation process. For this purpose, we use a USB data acquisition module with programmable I/O ports for control and signals acquisition for the complete system. The control software was developed using the graphical programming language LabVIEW® and compiled in order to obtain a portable system with the hardware used in this work.

Self-organized patterns by optical nonlinearity in 4-(4-pentenyloxy)benzonitrile

Optical characterization of the organic compound 4-(4-pentenyloxy)benzonitrile under two different conditions was carried out. The experiments show deformation of the scattered light spots upon heating as well as evidence of a thermally self-induced nonlinearity. In consequence, self-diffraction pattern, self-bending, and filamentation of the impinging beam appear as a function of the laser power, creating self-organized patterning during the filamentation due to modulation instabilities.

Self-diffraction properties in nanotubes (CNTs)

Nonlinear effects are consequence of interaction of height intensities of energy with the matter. Self-diffraction is nonlinear effect and rings are produced. We analyzed the increase of rings due to changes in intensity of CW Ar laser that modify the nonlinear refractive index. The Carbon Nanotubes (CNTs) were dispersed on different solvents: a) water, b) ethanol, c) isoprophanol, and d) acetone. The concentrations were 10ml:1mg in all samples. The dependence between power and concentration of CNTs is shown.

pH biosensor with plastic fiber optic doped with carbone nanotubes used sol-gel technique

We prepare optrodes of fiber optic plastic with sol-gel technique. Suitable concentration of carbone nanotubes (CNTs), phenol red, bromophenol blue and cresol red, design optrodes with fiber optic plastic. The surface charge of silica and the refractive index, which play an important roll on the fiber, modifies the conditions of light propagation into the plastic optical fiber. We use the transmittance to measure the pH of a solution or fluid in a range between 3 and 9.

Study of temperature sensing in a novel fattened electric arc induced LPFG

We propose a temperature sensor based on dispersion shifted long period fiber grating (LPFG) fabricated with the fattening method, using electric arc discharges from a commercial fusion splicer machine. The fattened LPFG are centered at 1524 and 1550 nm, respectively. A temperature characterization in terms of the transmitted spectrum is realized with a pumped Er+3 doped fiber as the light source. The less than 3 mm in length fattened LPFG reached a sensitivity of 72 pm/°C between a temperature range of (25-500°C). Temperature stability was observed among the temperature range of (25-200°C), result in agreement with our previous studies. From up to 200°C sensing is observed as temperature increases. To apply this LPFG as a temperature sensor, sensing was measured as voltage signal outputs with repeatable results. This sensor is a high temperature resistant device because non deterioration of its properties was observed, and can find useful applications when temperature stability may be needed or the sensing requirements are desirable.