Author: MIGUEL ANGEL BELLO JIMENEZ

Investigación de la extracción de solitones ópticos empleando un NOLM y su aplicación en el estudio del proceso de formación de solitones en fibras ópticas

MIGUEL ANGEL BELLO JIMENEZ (2010)

The soliton formation process in optical fibers is a complex and very interesting

phenomenon involving a variety of nonlinear phenomena. In particular it has been

demonstrated that the solitons appear in the fiber as a result of the interplay between

dispersive and nonlinear effects in the anomalous dispersion regime. However,

because of the cascaded nonlinear effects and its sensitive to experimental conditions,

a detailed comparison between theory and experiments is complicated. These

investigations are commonly carried out in an indirectly way, comparing simulate and

experimental spectra.

The selective extraction of solitons with desirable pulse duration could be very

useful for direct investigations of the soliton formation process and also for soliton

generation. To the best of our knowledge, the experimental demonstration of the

extraction of solitons with desirable pulse duration has not yet been reported. For this

reason in this PhD thesis is proposed the investigation of the soliton extraction by

using a nonlinear optical loop mirror (NOLM) and its application for investigations of

the soliton formation process in optical fibers.

The propose configuration consists of a symmetrical NOLM with highly twisted

low-birefringence fiber and a quarter wave retarder located asymmetrically into the

NOLM loop. We numerically investigate the nonlinear evolution of picosecond

pulses in a conventional fiber, where the pulse breaks up temporally forming a bunch

of fundamental solitons. The resulting solitons are launched into the NOLM whose

parameters are adjusted to transmit the highest intensity soliton. These results are

demonstrated experimentally by using 25-ps Gaussian pulses from a figure-eight fiber

laser configuration (F8L). For our particular case we report the extraction of a

fundamental soliton with pulse duration of 0.99 ps. The results reported in this thesis

demonstrate that the proposed method can be used to generate high-quality ultrashort

optical pulses, but also, it can be used for direct investigations of the initial stage of

the soliton formation process in optical fibers.

La formación de solitones en fibras ópticas es un fenómeno complejo y muy

interesante que involucra gran variedad de efectos no lineales. Se ha demostrado que

los solitones aparecen en la fibra como resultado de la interacción entre los efectos no

lineales y dispersivos en la región de dispersión anómala. Sin embargo, debido a la

cascada de efectos no lineales y su sensitividad a las condiciones experimentales, una

comparación detallada entre teoría y experimento es complicada. Estas

investigaciones son usualmente realizadas de forma indirecta, haciendo una

comparación entre los espectros simulados y experimentales.

La extracción selectiva de solitones con deseable duración temporal puede ser una

herramienta útil para investigar de forma directa el proceso de formación de solitones.

De nuestro conocimiento, la demostración experimental de la extracción de solitones

con deseable duración temporal es un proceso que no ha sido reportado aún. Por tal

motivo, en la presente tesis doctoral se propone la extracción no lineal de solitones

empleando un espejo de lazo óptico no lineal (NOLM) y su aplicación en el estudio

del proceso inicial de formación de solitones en fibras ópticas.

La configuración del sistema propuesto consiste de un NOLM simétrico con fibra

altamente torcida y un retardador de cuarto de onda en el lazo del NOLM.

Numéricamente investigamos la evolución no lineal de pulsos de picosegundos a

través de una fibra convencional, donde el pulso sufre una ruptura temporal y se

genera la formación de un tren de solitones fundamentales. Estos solitones son

introducidos al NOLM cuyos parámetros son ajustados para transmitir el solitón de

mayor intensidad. Estos resultados son demostrados experimentalmente empleando

pulsos gausianos de 25 ps, obtenidos a partir del diseño de un láser de fibra de figura

8 (F8L). Como caso particular reportamos la extracción de un solitón fundamental

con duración de 0.99 ps. Los resultados presentados en esta tesis demuestran que el

método propuesto puede ser empleado para generar pulsos ultracortos de alta calidad,

pero además, los resultados demuestran que el método propuesto puede ser empleado

para investigar la etapa inicial del proceso de formación de solitones en fibras ópticas.

Doctoral thesis

Fibre lasers Optical solitons Nonlinear optics CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA

Experimental investigation of the extraction of solitons at the initial stage of the soliton formation process

MIGUEL ANGEL BELLO JIMENEZ EVGENY KUZIN BALDEMAR IBARRA ESCAMILLA ARIEL FLORES ROSAS (2010)

We demonstrate the extraction of a single soliton from a bunch of solitons generated by the pulse breakup effect. The bunch of solitons was generated in a 500-m fiber pumped by 25-ps pulses. For the extraction of single soliton from the bunch we use a nonlinear optical loop mirror (NOLM). At its output we detected a pulse with full width at half-maximum (FWHM) of 0.99 ps whose autocorrelation trace corresponds to that of a soliton. Our results demonstrate that the suggested method can be useful for soliton generation, and also for investigations of the initial stage of the soliton formation process.

Article

Nonlinear optics, fibers Pulse propagation and temporal solitons. CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA ÓPTICA

Optimization of the two-stage single-pump erbium-doped fiber amplifier with high amplification for low frequency nanoscale pulses

MIGUEL ANGEL BELLO JIMENEZ EVGENY KUZIN BALDEMAR IBARRA ESCAMILLA ARIEL FLORES ROSAS (2007)

We report the two-stage single-pump configuration of an erbium-doped fiber amplifier, in which a Sagnac interferometer is introduced to reduce the most important contribution of amplified spontaneous emission (ASE) noise, providing significant improvement on the amplifier performance. A Sagnac interferometer, made from a high birefringence fiber loop, is included between the first and second stages. It is designed to provide transmittance with a period of 46 nm that allows us to adjust the minimum transmission around 1530 nm (peak of ASE noise) and maximum transmission at 1550 nm (signal wavelength). For optimizing the configuration, we measure the erbium-doped fiber parameters and simulate the amplification of the signal along the fiber. In the experiment, a significant absorption coefficient for pump and signal is found. The absorption looks to be too strong for the background absorption, and we suppose that it may be caused at least partly by excited state absorption (ESA). Including the absorption coefficient allows very good correspondence between simulation and experiment. Experimental results show that with a simple configuration, we obtain up to 53-dB amplification with only 73 mW of pump power.

Article

Erbium-doped fiber amplifiers Optical filters Sagnac interferometer CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA

Caracterización de un amplificador de fibra dopada con erbio a partir de sus parámetros experimentales

MIGUEL ANGEL BELLO JIMENEZ EVGENY KUZIN BALDEMAR IBARRA ESCAMILLA BARTOLO ROBERTO TELLEZ GARCIA (2007)

En este artículo presentamos un método sencillo para caracterizar la ganancia de un amplificador de fibra dopada con erbio (EDFA, erbium doped

fiber amplifier) mediante la simulación numérica de la propagación del haz de señal en el amplificador. La simulación se basa en

un modelo constituido por las ecuaciones de razón y propagación para una fibra dopada con erbio. La manipulación de este sistema de

ecuaciones nos permite hacer un reagrupamiento de los parámetros presentes en un EDFA, a los cuales hemos nombrado parámetros A, B,

C, D, y pueden obtenerse experimentalmente a partir de una fibra dopada con erbio. Los resultados obtenidos muestran que la medición de

estos parámetros nos permiten estimar con mucha precisión la ganancia del amplificador.

In this paper we describe a method to characterize the gain of an erbium-doped fiber amplifier (EDFA) through the numerical simulation of

the signal beam along the amplifier. The simulation is based on a model constituted by the propagation and rate equations for an erbium doped

fiber. The manipulation of these equations allows us to regroup the parameters present in an EDFA, which we have named the A, B,

C, D parameters, and they can be obtained experimentally from an erbium-doped fiber. Experimental results show that the measurement of

these parameters allow us to estimate with very good correspondence the amplifier gain.

Article

Erbio Amplificadores de fibra dopada con erbio Amplificadores ópticos Erbium Erbium-doped fiber amplifiers Optical amplifiers CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA

The use of NOLM for investigations of initial development of supercontinuum in fibers with anomalous dispersion¹

EVGENY KUZIN MIGUEL ANGEL BELLO JIMENEZ BALDEMAR IBARRA ESCAMILLA MANUEL DURAN SANCHEZ (2009)

We performed a numerical study of the transmission through a nonlinear optical loop mirror (NOLM) of a sequence of solitons enerated at the initial stage of the supercontinuum (SC) generation. We found that the NOLM exhibits a selective transmission that critically dependents on the amplitude of the input solitons and on the NOLM loop length. The results demonstrate that by properly selecting these parameters the NOLM behaves as an optically controlled switch that allows the transmission of solitons with similar amplitude and width. The results obtained by employing this method are reasonably good and can be used to analyze the soliton formation at the initial stage of SC generation.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA HOLOGRAFÍA

Fine adjustment of cavity loss by sagnac loop for a dual wavelength generation¹

ARIEL FLORES ROSAS EVGENY KUZIN MIGUEL ANGEL BELLO JIMENEZ BALDEMAR IBARRA ESCAMILLA (2010)

We experimentally demonstrate a fine adjustment of cavity loss by Sagnac loop for a dual wave-length generation. The single or dual wavelengths are obtained by controlling the losses on both cavities through a fiber optical loop mirror (FOLM). Wavelength separation on the dual laser is 0.98 nm. The dual or single wavelength is obtained by changes in temperature in the order of 10⁻¹°C around the maximum in the FOLM. Also, we investigate energy fluctuations on signal level saturation effect in the cavity through different pumping power that act on the EDF, where we note that from the 60-mW pumping begins to generate dual-wavelength and 80-mW stabilizes.

Article

Sagnac loop Fiber optical CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA ÓPTICA

Nonlinear optical correction of the pulse shape from a directly modulated DFB laser

JAIME GUTIERREZ GUTIERREZ EVGENY KUZIN MIGUEL ANGEL BELLO JIMENEZ BALDEMAR IBARRA ESCAMILLA ARIEL FLORES ROSAS (2008)

In this work, the effect of modulation instability (MI) in optical fiber is used to reshape nanosecond pulses form a directly modulated diode laser. Our configuration includes a fiber where MI causes the side lobes in the signal spectrum and a filter at the fiber output rejecting

the side lobes. Simulations show abrupt drop of the transmission of the setup if pulse power is above some critical value. We investigated the transmission for fibers with lengths in the range between 62-m and 4.5-km. The critical power was found to be inversely proportional to the fiber length. An average scaled critical power is 2.16W km. We demonstrated the application of the method for rejection of the transient peak in a directly modulated diode laser.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA OPTICA NO LINEAL

Experimental investigation of the extraction of solitons at the initial stage of the soliton formation process

MIGUEL ANGEL BELLO JIMENEZ EVGENY KUZIN BALDEMAR IBARRA ESCAMILLA ARIEL FLORES ROSAS (2009)

We demonstrate the extraction of a single soliton from a bunch of solitons generated by the pulse breakup effect. The bunch of solitons was generated in a 500-m fiber pumped by 25-ps pulses. For the extraction of single soliton from the bunch we use a nonlinear optical loop mirror (NOLM). At its output we detected a pulse with full width at half-maximum (FWHM) of 0.99 ps whose autocorrelation trace corresponds to that of a soliton. Our results demonstrate that the suggested method can be useful for soliton generation, and also for investigations of the initial stage of the soliton formation process.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA OPTICA NO LINEAL

Wavelength-tunable picosecond pulses from a passively mode-locked figure-eight erbium-doped fiber laser with a sagnac fiber filter

BALDEMAR IBARRA ESCAMILLA EVGENY KUZIN MIGUEL ANGEL BELLO JIMENEZ ARIEL FLORES ROSAS (2008)

We experimentally demonstrated a wavelength-tunable passively mode-locked Erbium-doped figure-eight fiber laser. Wide tunability is achieved using a high-birefringence (hi-bi) fiber Sagnac loop. The filter transmission pass wavelength is controlled by thermally adjusting the hi-bi fiber loop length. The output pulses are wavelength tunable over a range from 1525 nm to 1555 nm. The FWHM of the autocorrelation trace is about 3.1 ps and the pulse spectrum has a FWHM of 1.5 nm. The pulse temporal and spectral widths remain constant over the tunable range.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA FIBRAS ÓPTICAS