Vol. 2 No. 1 Jan-Mar (2021): Suplemento de la Revista Mexicana de Física. Física de fibras ópticas en México, en memoria del Dr. Evgeny A. Kuzin
Este volumen especial para el Suplemento de la Revista Mexicana de F´ısica cubre diferentes l´ıneas de desarrollo e investigaci´on en el ´area de fibras ´opticas en M´exico y est´a dedicado a la memoria de nuestro respetado Colega y querido amigo el Prof. Evgeny A. Kuzin.
Guest Editors:
Baldemar Ibarra-Escamilla, Instituto Nacional de Astrof´ısica Óptica y Electrónica, México.
Serguei Stepanov, Centro de Investigaci´on Cient´ıfica y de Educaci´on Superior de Ensenada, México.
Roberto Rojas-Laguna, DICIS, Universidad de Guanajuato, M´exico.
05 FÍSICA DE FIBRAS ÓPTICAS EN MÉXICO, EN MEMORIA DEL DR. EVGENY A. KUZIN
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Preface
Abstract:⬇️ Scroll down to see the full summaryEste volumen especial para el Suplemento de la Revista Mexicana de F´ısica cubre diferentes l´ıneas de desarrollo e investigaci´on en el ´area de fibras ´opticas en M´exico y est´a dedicado a la memoria de nuestro respetado Colega y querido Amigo el Prof. Evgeny A. Kuzin.
Versar sobre el legado de Prof. Kuzin, asume honrar un di´alogo sobre un Ser Humano extraordinario sin precedente. -
Complex dynamics of passively mode-locked fiber lasers with strict polarization control
Abstract:In this work we browse an overview of the complex dynamics that arise in the non-stationary modes of operation of partly mode-locked fiber lasers under strict polarization control. Both ring and figure-eight cavities implementing saturable absorber mechanisms that rely on nonlinear polarization rotation were considered. The use of twisted fiber ensures robust operation, whereas precise polarization adjustments allow tailoring the nonlinear switching characteristic in a clear and repeatable manner. The enhanced flexibility of these sources allowed identifying and studying a broad spectrum of peculiar dynamics, in particular by implementing the temporal and spectral mapping techniques. These include the emergence, fusion, splitting, complex evolution and eventual decay of chaotic bunches of radiation, which are also subject to large spectral shifts, ample quasi-periodic instabilities, extreme-intensity events or the creation of solitons, among others, as well as the complex evolution of massively multiple soliton states. Finally, with the help of numerical simulation, several aspects of the physics underlying these puzzling behaviors could be elucidated.⬇️ Scroll down to see the full summary -
Optical-fiber ring cavity with saturable rare-earth-doped fiber
Abstract:⬇️ Scroll down to see the full summaryResonance properties of the all-fiber ring cavity filled with nonlinear material - saturable rare-earth-doped fiber are analyzed and experimentally investigated. Unlike the earlier investigated erbium-doped fiber at 1550nm where the optical absorption photo-induced change (saturation) is observed only, the ytterbium-doped fiber at 1064nm demonstrates the saturation of the refractive index mainly. For this configuration we report experimental observation of the optical bistability and hysteresis in the transmitted output light at the 10mW-scale incident light power. The experimental results are in qualitative agreement with the theoretical analysis that takes into account the saturation of both parameters: the optical absorption and the refractive index of the doped fiber. The reported results seem promising for applications in high-sensitivity interferometric configurations at 1064nm operation wavelength.
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Ajuste de resonancia doble en láseres de Brillouin de fibra óptica
Abstract:⬇️ Scroll down to see the full summaryReportamos una solución técnica simple para un ajuste preciso de la longitud de cavidades cortas de fibra óptica usadas comúnmente en los láseres de Brillouin. La cavidad ajustada del láser es simultáneamente resonante para el bombeo y la emisión de Stokes. La técnica propuesta está basada en registrar la respuesta de Brillouin de la cavidad a un escaneo frecuencial de la emisión del láser de bombeo. Las trazas almacenadas son utilizadas para calcular el exceso de longitud de la cavidad que necesita ser removido de la cavidad original para un ajuste preciso de la resonancia de Brillouin en cualquier longitud de onda preseleccionada del láser de bombeo. Para la comprobación de su funcionamiento se desarrolló el ajuste fino de una cavidad de anillo basada en fibra estándar SMF-28 de Corning de 4 m de longitud. Además, se presenta un análisis detallado del error en el algoritmo de ajuste de la doble resonancia en la cavidad de anillo de fibra del láser de Brillouin de corta longitud. La propuesta presentada es igual de útil para el diseño de láseres de fibra monomodo de espectro óptico ultra-angosto y láseres de fibra de Brillouin Q-switched, así como para aplicaciones que emplean alta potencia en cavidades de fibra que evitan la dispersión de Brillouin estimulada.
We report a simple technical solution for precise adjustment of short fiber cavities commonly used with Brillouin fiber lasers. The adjusted laser cavity is simultaneously resonant for pump and Stokes radiations. The technique is based on recording the Brillouin response of the cavity to the frequency scanned laser radiation. The recorded traces are used to calculate the excess cavity length that needs to be removed from the original cavity to provide its precise adjustment to the Brillouin resonance at any preselected pump laser wavelength. For demonstration of the approach, fine adjustment of a 4 m long ring cavity based on standard Corning SMF-28 fiber is performed. A detailed error analysis of the algorithm for adjustment of double resonance in short-length Brillouin ring fiber laser was presented. Demonstrated approach is equally useful for the design of single mode fiber lasers with ultra-narrow optical spectra, Q-switched Brillouin fiber lasers as well as for applications employing high power fiber cavities free from stimulated Brillouin scattering.
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Polarization control for fiber systems and devices
Abstract:⬇️ Scroll down to see the full summaryNulling the birefringence effect of a light signal traveling through a single-mode fiber when the fiber behaves as an elliptical retarder can be achieved by winding the fiber as a double-helix. We present a resume of the theory and procedures developed at CICESE to demonstrate this polarization control in fiber systems.
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Ferrofluidic sensitive element in fiber optics
Abstract:This article discusses problems related to the use of ferrofluid, infiltrated in a microstructured optical fiber and controlled by an external magnetic field. It summarizes the results obtained by the authors on a fiber filled with this substance and subjected to harmonic or impulse field action. It is shown that magneto-optical effects are observed here, which significant for designing tunable fiber elements.⬇️ Scroll down to see the full summary -
Numerical study of the polarization proprieties in a ring cavity with total polarization control
Abstract:⬇️ Scroll down to see the full summaryWe report the numerical study of the polarization properties of a net anomalous dispersion ring cavity with total polarization control. As a mode locker, we use the nonlinear polarization rotation (NPR) method. The initial ellipticity and azimuth were fixed to 13° and 0°, respectively. The simulations, made by the split-step Fourier method, show changes in polarization with respect to initial conditions, after the mode-lock process such as previously reported in the literature. It was found that polarization changes are caused by non-linear birefringence. The pulsed laser produces solitonic pulses with 0.4 ps FWHM and 240 W peak power.
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Tip optical fiber refractive index sensor based on a thin copper film
Abstract:⬇️ Scroll down to see the full summaryWe report a refractive index tip fiber optic sensor based on a modal interferometer coated with a thin copper film. This device can be used for solute concentration in aqueous mixture measurement. The copper film increases the device reflectivity and, as a result, increases the multimodal interference pattern visibility. To validate the sensor device, different water-glycerol weight concentrations were used in the range from 0 to 45 Glycerol %. The recorded spectral responses show a redshifting, and a sensitivity of 19 pm / (Glycerol % by weight) from 0 to 18 % and 4.7 pm / (Glycerol % by weight) from 18 to 45 % was achieved. Besides, using a phase analysis we calculated a sensitivity of -15 rad/RIU.
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Generation of dissipative soliton resonance in a fiber laser based on a nonlinear optical loop mirror
Abstract:⬇️ Scroll down to see the full summaryWe experimentally demonstrate generation of mode-locked pulses in dissipative soliton resonance (DSR) regime. The DSR pulses are obtained from a passively mode-locked figure-8 Er:Yb doped fiber laser operating in large net anomalous dispersion regime. The modelocked laser emission is based on a polarization-imbalanced nonlinear optical loop mirror (NOLM), acting as artificial saturable absorber. Stable square DSR pulses, obtained by carefully adjusting the NOLM properties, increase their duration from 2.47 ns to 46.52 ns as the pump power is increased from 0.68 to 6.31 W. With the maximum pump power launched, average output power of 73.95 mW with pulse energy of 53.39 nJ is achieved.
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The nonlinear optical loop mirror: soliton and noise-like pulse emission in a figure-eight fiber laser
Abstract:In this article, a symmetrical nonlinear optical loop mirror (NOLM) exhibiting a polarization-dependent transmission is evaluated to generate optical pulse emission in a figure-eight fiber laser in the soliton and noise-like pulse (NLP) regimes. The NOLM structure relies on a 50:50 fiber coupler, a loop with highly twisted single-mode optical fiber and a quarter-wave retarder (QWR) to break the polarization asymmetry. The pulse operation regime is determined by properly adjusting the NOLM low-power transmission, which is easily realized by the rotation of the QWR angle. Soliton pulses of 1.48 ps pulse duration and peak power of 18 W were observed with a peak to peak separation of 1.25 µs, corresponding to a fundamental cavity repetition rate of 0.8 MHz. Moreover, by incrementing the NOLM low-power transmission, NLP emission is generated exhibiting a wide and smooth spectrum of 8.5 nm bandwidth.⬇️ Scroll down to see the full summary -
Analysis of spectral broadening dominated by cascaded stimulated Raman scattering in optical fibers
Abstract:⬇️ Scroll down to see the full summaryIn this work, the experimental study of spectral broadening due to stimulated Raman scattering with respect to variation of input power of pulsed laser, as well as a 4 m length high-numerical aperture fiber with 100 and 500 m of non-zero dispersion-shifted fiber is reported. The results showed extreme broadening of spectrum which is known as supercontinuum generation, originated by self-phase modulation, four- wave mixing and dominated by cascaded stimulated Raman scattering. Supercontinuum spectrum achieved by total width of 850 nm and a remarkable flatness in the range of 1500 to 1600 nm. Furthermore, output spectrum showed a total of five Stokes waves. Numerical results are also presented.
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Fiber laser refractometer operating in the 2 μm spectral region based on the MMI effect
Abstract:⬇️ Scroll down to see the full summaryWe experimentally demonstrate a fiber laser refractometer based on the use of a multimode interference (MMI) fiber structure. The MMI filter is constructed with an uncladded fiber segment which acts as sensing element to determine the refractive index (RI) of liquid solutions. The laser emission, generated at the 2 μm waveband, is wavelength shifted in linear proportion to the RI of the liquid. The proposed fiber laser refractometer exhibits high sensibility of 937.81 nm/RIU.
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Impact of higher-order optical fiber modes for photon-triplet generation
Abstract:⬇️ Scroll down to see the full summaryThis paper presents a study of the phasematching properties of the third-order parametric down-conversion process in multimode optical fibers with a step-index profile. Through this process, entangled photon triplets can be generated in the spontaneous regime. We show that phasematching is achieved in a wide range of fiber geometries, provided that the pump field propagates in a higher-order mode. Furthermore, we show the nonlinear coefficient and the absolute emitted flux for each source configuration, evaluated from expressions derived by us in previous theoretical studies concerning the spontaneous and stimulated emission regimes.
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Analysis of whispering gallery modes resonators: wave propagation and energy balance models
Abstract:⬇️ Scroll down to see the full summaryElectromagnetic whispering gallery modes (WGM) are surface waves guided by the curvature of an interface. Microspheres, microdisks and microcylinders –as for example standard optical fibers– are high quality microresonators for the WGM. In fact, they can be regarded as compact and small ring resonators. Here, we present a comparison between wave propagation and energy balance models, stablishing the equivalence and discussing the basic characteristics of these two complementary approaches.
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Correlation technique using of-the-shelf CW DFB laser for interrogation of fiber optic sensors
Abstract:⬇️ Scroll down to see the full summaryThe paper presents a simple fiber-optic sensor technique based on methods of correlation optical time domain reflectometry. A correlation reflectometry technique can measure distribution of reflection coefficient along the optical fiber by calculating the correlation function between a probe optical signal (reference) and the signal returned back due to reflections or/and back-scattering from the fiber under the test. To obtain the best sensor performance, the probe signal power should be a truly random function of time. As an optical source we use a free-running DFB laser diode operating in a continuous wave regime without any external modulation. To generate the probe test signal, laser light is passed through an interferometer with an optical path difference much longer than the coherence length of the laser light. The light intensity at the interferometer output has a truly random fluctuations and its auto correlation function is suitable for correlation optical reflectometry. We present results of experimental verification of the techniques in different sensor configurations. Multipoint sensor using very low reflective fiber Bragg gratings with reflectivity of 0.01% printed in a long SMF-28 optical fiber was demonstrated.
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Review of SDM/WDM technology and its application in data transmission
Abstract:⬇️ Scroll down to see the full summaryIn this paper we present a review focused on Space Division Multiplexing (SDM) technology. A summary of the most recent works on innovation in the efficiency of SDM as well as its application in data transmission is described. SDM is a technology that has improved the capacity of optical communication systems. Combined with other optical technologies has significantly increased the capacity of information that is sent through an optical fiber.
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Fiber optic system to measure adulteration in liquids using an RGB detection
Abstract:⬇️ Scroll down to see the full summaryIn this paper, we propose a fiber optic system to measure the changes in the RGB composition of light in liquid solutions using a plastic optical fiber (POF) as an intrinsic sensor. The measurement system is composed of a 3 W white light-emitting diode as the light source, a 20 cm long U-shaped POF, and an RGB photodiode array that allows us to detect the changes in the RGB composition of the light propagating through the POF. The U-shaped POF has a length of 5 mm without coating, which remains in contact with the liquid solutions. The tests were performed with different concentrations of a mixture of tequila and water. The results obtained with the RGB photodiode array showed that the system has a resolution of 0.39 % and a color change sensitivity of 0.1, 0.6, and 0.4 8–bits/% of sample for red, green, and blue colors, respectively. These results will allow us to design a low-cost prototype to measure the amount of adulteration in liquids.
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Alcohols detection by a polymeric sensing film deposited on a long-period fiber grating
Abstract:In this paper, we report the construction and characterization of a sensor to detect volatile organic compounds, particularly alcohols. The sensor was fabricated by depositing a polydimethylsiloxane sensing film on the surface of a long-period fiber grating (LPFG). The LPFG spectrum, which was taken as the sensor response, was measured in a Teflon chamber, where different concentrations of methanol, ethanol, propanol, and butanol samples were injected. Spectral shifts to lower wavelength were observed for the last three samples. However, a shift to higher wavelengths for the case of methanol was observed, which was attributed to the fact that its refractive index is smaller than the one for PDMS. Therefore, curves of the sensor response in function of concentration were performed using different analysis techniques: analysis in a fixed wavelength, analysis in a fixed spectrum amplitude and spectral analysis trough principal components analysis (PCA) method. The results showed a regular behavior of the responses according to the molecular weight of the samples. A discussion of the use of each technique was performed.⬇️ Scroll down to see the full summary -
Temperature Sensor Using Fiber Ring Laser Based On a Core-Offset Mach-Zehnder Interferometer
Abstract:The development of fiber optic sensors receives special interest since they can be used in multiple applications. As a result, fiber optic laser-sensor schemes had emerged as a reliable device, due to its characteristics such as: high power, low threshold, and high stability. In this work, it is proposed a fiber laser-sensor based on a ring cavity configuration. The cavity is operated by a core-offset Mach-Zehnder interferometer, which is used as a wave selection filter and temperature detection device. Here, the proposed fiber laser-sensor exhibits sensing properties such as sensitivity of 0.03119 pm/°C , dynamic range of 90ºC and a signal to noise ratio of 52 dB⬇️ Scroll down to see the full summary -
Noise fiber lasers
Abstract:In this paper, we present a brief review of the noise operation mode of fiber lasers. These lasers were studied recently by collaborative group that includes researchers, professors, and Ph.D. students from the Centro de Investigaciones en Optica, A.C. (Leon, Guanajuato, Mexico) and from the Universidad de Valencia (Valencia, Spain). Meanwhile, the pioneer works in this topic important for understanding the physics behind fiber lasers’ operation and for practical applications were done with the active participation of Dr. Evgeny Kuzin from the Instituto Nacional de Astrofisica, Optica y Electronica (Puebla, Mexico) and Dr. Georgina Beltrán-Pérez from the Benemérita Universidad Autónoma de Puebla (Puebla, Mexico), whose Ph.D. study was supervised by him. The fiber lasers under study were based on commercial erbium- and ytterbium-doped fibers as gain media and operated in continuous-wave and actively Q-switched regimes. All these fiber lasers were arranged in Fabry-Perot cavity configuration with fiber Bragg gratings as narrow-band reflectors. In the case of actively Q-switched lasers a standard fiberized acousto-optic modulator was placed close to the rear (100%) reflector. The most important conclusion of all the works grounding the present review is that, independently on laser operation regime, continuous wave or actively Q-switched, these fiber lasers operate in the extremely noise regime with the photon statistics described by Bose-Einstein distribution inherent to narrow-band thermal light sources.⬇️ Scroll down to see the full summary
