scispace - formally typeset
Search or ask a question

Showing papers on "Fiber laser published in 1997"


Journal ArticleDOI
TL;DR: In this paper, the authors review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings and intragrating sensing concepts.
Abstract: We review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings, intragrating sensing concepts, long period-based grating sensors, fiber grating laser-based systems, and interferometric sensor systems based on grating reflectors.

3,665 citations


Journal ArticleDOI
TL;DR: A theoretical model indicates that this mode of operation can be explained by the internal birefringence of the laser cavity combined with a nonlinear transmission element and the gain response of the fiber amplifier.
Abstract: An erbium-doped fiber laser that produces a train of intense noiselike pulses with a broadband spectrum and a short coherence length is reported. The noiselike behavior was observed in the amplitude as well as in the phase of the pulses. The maximum spectral width obtained was 44 nm. The high intensity and the short coherence length of the light were maintained even after propagation through a long dispersive fiber. A theoretical model indicates that this mode of operation can be explained by the internal birefringence of the laser cavity combined with a nonlinear transmission element and the gain response of the fiber amplifier.

457 citations


Journal ArticleDOI
Clinton Randy Giles1
TL;DR: Fiber Bragg gratings (FBGs) have emerged as important components in a variety of lightwave applications and their unique filtering properties and versatility as in-fiber devices is illustrated by their use in wavelength-stabilized lasers, fiber lasers, remotely pump amplifiers.
Abstract: Fiber Bragg gratings (FBGs) have emerged as important components in a variety of lightwave applications. Their unique filtering properties and versatility as in-fiber devices is illustrated by their use in wavelength-stabilized lasers, fiber lasers, remotely pump amplifiers. Raman amplifiers, phase conjugators, wavelength converters, passive optical networks, wavelength division multiplexers (WDMs) demultiplexers, add/drop multiplexers, dispersion compensators, and gain equalizers.

383 citations


Journal ArticleDOI
TL;DR: Er3+-doped tellurite singlemode fiber is fabricated and signal amplification and laser oscillation are demonstrated for the first time in this article, where a small signal gain of 16 dB at 1560 nm is obtained for a pump power of 130 mW at 978 nm.
Abstract: Er3+-doped tellurite singlemode fibre is fabricated and signal amplification and laser oscillation are demonstrated for the first time. A small-signal gain of 16 dB at 1560 nm is obtained for a pump power of 130 mW at 978 nm. A laser oscillation is observed with a threshold pump power of 120 mW at 978 nm and a slope efficiency of 0.65% using this fibre.

294 citations


Journal ArticleDOI
TL;DR: A new mechanism for passive Q switching of fiber lasers is discovered and 10-kW peak power pulses with ~2-ns pulse widths are reported from a diode-pumped ytterbium-doped fiber laser.
Abstract: We have discovered a new mechanism for passive Q switching of fiber lasers. 10-kW peak power pulses with ∼2-ns pulse widths are reported from a diode-pumped ytterbium-doped fiber laser. The laser generates a high-brightness Raman-dominated supercontinuum spectrum covering the complete window of transparency of silica fiber in the infrared from 1.06 to 2.3 µm

282 citations


Journal ArticleDOI
TL;DR: In this article, the authors show that low time jitter of a harmonic passively mode-locked laser can be obtained at repetition rates close to acoustic eigenfrequencies of the optical fiber.
Abstract: We show that low time jitter of a harmonic passively mode-locked laser can be obtained at repetition rates close to acoustic eigen-frequencies of the optical fibre.

238 citations


Patent
21 Feb 1997
TL;DR: In this article, a system-level optical measurement probe would include a laser, a spectrometer, a first optical fiber to carry energy from the laser to a sample, including a Bragg grating laser bandpass filter at its tip, and a second optical fiber, which would have included within it at its distal tip an optical filter to selectively reject energy associated with the nominal wavelength.
Abstract: Laser band-pass filter and/or band-reject filters are located at the end of an optical measurement probe by placing an appropriate Bragg grating proximate to the tip, and within, one or both of the optical fibers that make up the probehead. Thus, where an optical fiber is used to carry excitation energy of a nominal wavelength to a sample, the distal tip of this fiber will have included therein an optical filter to selectively pass energy of the nominal wavelength. Similarly, where an optical fiber is employed to carry stimulated emission from the sample to an analytical instrument such as a spectrometer, this fiber will have included within it at its distal tip an optical filter to selectively reject energy associated with the nominal wavelength. A disclosed system-level optical measurement probe would include a laser, a spectrometer, a first optical fiber to carry energy from the laser to a sample, including a Bragg grating laser bandpass filter at its tip, and a second optical fiber to carry energy collected from the sample to the spectrometer, including a Bragg grating laser band-reject filter at its tip.

214 citations


Journal ArticleDOI
TL;DR: Frequency doubled an externally chirped erbium-doped fiber laser generating 17-ps pulses at 1560nm to produce near-transform-limited 110-fs (FWHM) pulses at 780nm by use of a 5-cm-long lithium niobate crystal poled with a QPM grating.
Abstract: We demonstrate the use of an aperiodic quasi-phase-matching (QPM) grating to generate second-harmonic pulses that are stretched or compressed relative to input pulses at the fundamental frequency. We frequency doubled an externally chirped erbium-doped fiber laser generating 17-ps (FWHM) pulses at 1560 nm to produce near-transform-limited 110-fs (FWHM) pulses at 780 nm by use of a 5-cm-long lithium niobate crystal poled with a QPM grating chirped from an 18.2- to a 19.8-µm period.

199 citations


Journal ArticleDOI
TL;DR: In this paper, the thermal decay of fiber bragg gratings with and without hydrogen loading was examined over a period in excess of 5000 h and it was shown that the non-hydrogen loaded gratings do not obey the power law model.
Abstract: Fiber Bragg gratings (FBGs) have been written in silica fiber codoped with boron and germanium, using a continuous-wave (CW) 244-nm laser. The thermal decay of the gratings written with and without hydrogen loading is examined over a period in excess of 5000 h. It is shown that the thermal decay of the nonhydrogen loaded gratings is well explained by the power law model proposed by Erdogan. Gratings written in hydrogen loaded fiber, however, do not obey the power law model. A new model is presented based on a log time representation which can be used to predict the decay characteristics of gratings written in hydrogen loaded fiber.

192 citations


Journal ArticleDOI
TL;DR: In this paper, a wavelength-swept fiber laser (WSFL) incorporating frequency shifted feedback and an intracavity passband filter is considered, in which the wavelength of the modeless output is linearly, continuously and repeatedly tuned (in time) by modulation of the filter peak wavelength and filter strength.
Abstract: This paper concerns a wavelength-swept fiber laser (WSFL) incorporating frequency shifted feedback and an intracavity passband filter, in which the wavelength of the modeless output is linearly, continuously and repeatedly tuned (in time) over a given range by modulation of the filter peak wavelength and filter strength. We show both numerically and experimentally that amplifier noise plays a key role in determining the operation of frequency-shifted fiber laser systems and that a "noisy" amplifier can be used to suppress the natural tendency of such lasers to pulse, allowing for continuous wave, modeless operation. Furthermore, we show that significant narrowing of a WSFL instantaneous swept linewidth can be obtained if the filter peak transmission wavelength is resonantly swept so as to follow the wavelength shift per pass due to the acoustooptic frequency shift. Using these ideas we go on to demonstrate and characterize a high-power diode-driven Er/sup 3+//Yb/sup 3+/ WSFL incorporating a bulk-optic acoustooptic tunable filter (AOTF). Linewidths as narrow as 9 GHz, sweep ranges up to 38 nm and output powers as high as 100 mW are obtained. Furthermore, we demonstrate the generation of user definable average spectral output by synchronous modulation of the filter strength and multiwavelength pulsed output at higher sweep rates. Excellent agreement between the experimental results and those of the numerical modeling is obtained. Our simulations show that reduced linewidth (<0.02 nm) and improved scan linearity should be readily achievable with realistic system improvements. We believe such sources to be of considerable physical and practical interest, with applications ranging from sensor array monitoring and device characterization through to low-coherence interferometry.

173 citations


Book ChapterDOI
01 Jan 1997
TL;DR: In this article, the authors review the methods of producing rare earth-doped fiber and the effect of the host composition and the rare earth doping on the quality of the final product.
Abstract: Several technical revolutions over the last ten years have led to the increasing use of rare earth-doped fiber lasers and amplifiers as a key component of optical communication systems. In this chapter, we review the methods of producing these fibers and the effect of the host composition and the rare earth doping on the quality of the final product. We then review the physics of the dopants and the hosts involved which makes these doped fibers so valuable for optical communications. In the last section, the laser performance itself is summarized; new trends for the future are presented.

Journal ArticleDOI
TL;DR: A photon avalanche process was found to contribute strongly to the population of the upper laser level of a Pr, Yb-doped ZrF(4)-BaF(2)-LaF(3)-AlF( 3)-NaF fiber in the red spectral region.
Abstract: We report cw laser emission of a Pr, Yb-doped ZrF(4)-BaF(2)-LaF(3)-AlF(3)-NaF fiber in the red spectral region. Laser emission was achieved on the transition P(0)(3)?F(2)(3)(lambda(L)=635 nm) with a Ti:sapphire pump laser tuned to lambda(p)=850 nm . A maximum output power of P(out)=675 mW was obtained at an incident pump power of P(in)=3.37 W . The output power was increased to P(out)=1020 mW when pumping with P(in)=5.51 W was provided by two Ti:sapphire lasers. A photon avalanche process was found to contribute strongly to the population of the upper laser level.

Journal ArticleDOI
TL;DR: Both single-frequency Bragg-grating reflector and distributed-feedback lasers with slope efficiencies of 25% with respect to launched pump power have been realized in photosensitive Er/Yb-doped fibers.
Abstract: Boron- and germanium-doped highly photosensitive cladding is used in a novel design to achieve photosensitive Er/Yb-doped fibers, permitting short, strong gratings (length ≈1 cm, reflectivity >99%) to be written without hydrogenation. The high absorption at 980 nm in Er/Yb fibers permits efficient pump absorption over a short device length, which is ideal for achieving highly efficient single-frequency fiber lasers. Both single-frequency Bragg-grating reflector and distributed-feedback lasers with slope efficiencies of 25% with respect to launched pump power have been realized in such fibers.

Journal ArticleDOI
TL;DR: The fluoride fiber laser with the longest emission wavelength, the Ho(3+)-transition at 3.9 mum in the attenuation minimum of the 3-5-mum atmospheric window, is characterized and room-temperature fluorescence and laser action with liquid-nitrogen cooling is described.
Abstract: The fluoride fiber laser with the longest emission wavelength, the Ho(3+)-transition at 3.9 mum in the attenuation minimum of the 3-5-mum atmospheric window, is characterized. After reviewing the importance of fluoride fibers due to their low phonon energies, we describe room-temperature fluorescence and laser action with liquid-nitrogen cooling. Continuous-wave laser action at 3.9 mum is presented for the 640- and the 890-nm pump ranges. A shift of the emission wavelength is achieved by varying the resonator mirrors. Laser characteristics and temperature dependence are discussed.


Journal ArticleDOI
TL;DR: In this paper, the optical properties of rare-earth organic complexes have been studied because of their possible application to polymer optical fibers and waveguides, and numerical simulations reveal that gains as high as and exceeding 20 dB should be realizable in rare earth-doped polymer fiber amplifiers having lengths <60 cm.
Abstract: The optical properties of rare-earth organic complexes have been studied because of their possible application to polymer optical fibers and waveguides. Er3+, Nd3+, and Sm3+ ions are encapsulated in tetrakis(benzoyltrifluoroacetonate) and tetrakis(dibenzoylmethide) chelates, and their radiative properties are evaluated in several organic solvents. Analysis reveals that tetrakis(benzoyltrifluoroacetonate) chelates are promising dopants for use in rare-earth-doped polymer devices. These rare-earth complexes can be doped to high concentrations in polymer systems without quenching, providing the means for short-length amplification devices. Numerical simulations reveal that gains as high as and exceeding 20 dB should be realizable in rare-earth-doped polymer fiber amplifiers having lengths <60 cm. Similar calculations reveal threshold pump powers of tens of milliwatts for rare-earth-doped polymer fiber lasers.

Journal ArticleDOI
TL;DR: In this paper, the use of fiber gratings in conjunction with erbium-doped fiber amplifiers (EDFAs), fiber lasers, and with semiconductor diode lasers is reviewed.
Abstract: The emergence of UV-written fiber gratings, both short and long period, as a reliable fiber technology has revolutionized the field of active fiber devices. The advantageous properties of spectral selectivity, low insertion loss, and component ruggedness have made devices possible that would not be viable without their use. The use of fiber gratings in conjunction with erbium-doped fiber amplifiers (EDFAs), fiber lasers, and with semiconductor diode lasers is reviewed.

Journal ArticleDOI
TL;DR: This is the first demonstration of a portable high-precision gas sensor based on diode-pumped DFG at room temperature and it employed a compact multipass absorption cell with a 18-m path length and a thermoelectrically cooled HgCdTe detector.
Abstract: Design and operation of a compact, portable, room-temperature mid-infrared gas sensor is reported. The sensor is based on continuous-wave difference-frequency generation (DFG) in bulk periodically poled lithium niobate at 4.6 µm, pumped by a solitary GaAlAs diode laser at 865 nm and a diode-pumped monolithic ring Nd:YAG laser at 1064.5 nm. The instrument was used for detection of CO in air at atmospheric pressure with 1 ppb precision (parts in 109, by mole fraction) and 0.6% accuracy for a signal averaging time of 10 s. It employed a compact multipass absorption cell with a 18-m path length and a thermoelectrically cooled HgCdTe detector. Precision was limited by residual interference fringes arising from scattering in the multipass cell. This is the first demonstration of a portable high-precision gas sensor based on diode-pumped DFG at room temperature. The use of an external-cavity diode laser can provide a tuning range of 700 cm-1 and allow the detection of several trace gases, including N2O, CO2, SO2, H2CO, and CH4.

Journal ArticleDOI
TL;DR: In this article, a short cavity erbium/ytterbium fiber laser with a saturable Bragg reflector is presented, which produces sub-500-fs pulses at fundamental cavity repetition rates as high as 300 MHz.
Abstract: We present short cavity erbium/ytterbium fiber lasers that are passively mode-locked with a saturable Bragg reflector. The lasers produce sub-500-fs pulses at fundamental cavity repetition rates as high as 300 MHz. Stable passive harmonic operation increases the repetition rate to 2.0 GHz. The mode-locking mechanism in both the normal and anomalous group velocity dispersion regimes is investigated using complete analytical and numerical models and direct comparison with the experimental results. A simple technique for accurately measuring the total cavity dispersion is presented.

Journal ArticleDOI
TL;DR: In this article, an efficient continuous-wave (CW) thulium-doped fiber laser emitting at wavelength, /spl lambda/=2.31 /spl mu/m is reported.
Abstract: Operation of an efficient continuous-wave (CW) thulium-doped fiber laser emitting at wavelength, /spl lambda/=2.31 /spl mu/m is reported. The fiber laser parameters are optimized with a view to ultimately producing a compact and efficient laser source for optical absorption based gas sensing. A number of fiber laser configurations are investigated to assess their suitability for narrow linewidth, tunable fiber laser operation emitting around /spl lambda/=2.3 /spl mu/m, which is a wavelength region of significant importance for hydrocarbon gas monitoring. Tuning ranges of 140 nm and linewidths of less than 210 MHz have been demonstrated with lasers with bulk external tuning grating. Preliminary hydrocarbon gas sensing investigation confirm the potential of this source for detection of ppb gas concentrations.

Journal ArticleDOI
TL;DR: In this paper, the authors present a detailed discussion of the operation of hybrid Brillouin/erbium fiber laser (BEFL) for single and multiple wavelength generation and modeling of single wavelength operation.
Abstract: Brillouin/erbium fiber lasers (BEFLs) have been recently demonstrated as a novel mode of operation of a fiber laser. In a hybrid Brillouin/erbium fiber laser, the combination of two gain media, the gain from the erbium-doped fiber (EDF) and Brillouin gain in single-mode optical fibers allows a resonator to be constructed which supports a laser comb with /spl sim/10 GHz or /spl sim/0.1 nm line spacing at room temperature. In this paper, we present a detailed discussion of the operation of BEFLs. Single and multiple wavelength generation is discussed, and modeling of single wavelength operation is described.

Journal ArticleDOI
TL;DR: Quasi-phase-matched second-harmonic generation in periodically poled lithium niobate is used to generate 8.1 mW of 190-fs, 90-pJ pulses at 777 nm with a conversion efficiency greater than can be obtained with existing birefringently phase-matched nonlinear materials.
Abstract: We report efficient frequency doubling of passively mode-locked femtosecond erbium-fiber lasers. Quasi-phase-matched second-harmonic generation in periodically poled lithium niobate is used to generate 8.1 mW of 190-fs (FWHM), 90-pJ pulses at 777 nm with a conversion efficiency greater than can be obtained with existing birefringently phase-matched nonlinear materials. A dispersion-compensation-free soliton oscillator generating transform-limited 230-fs (FWHM) pulses at 1554 nm is used as a pump laser.

Journal ArticleDOI
TL;DR: A modelocked fiber laser, operating in the soliton regime without any explicit intracvity polarizers, is observed to spontaneously lock its output polarization for certain values of the intracavity birefringence.
Abstract: A modelocked fiber laser, operating in the soliton regime without any explicit intracavity polarizers, is observed to spontaneously lock its output polarization for certain values of the intracavity birefringence. For other settings of the intracavity birefringence the output polarization undergoes pulse-to-pulse evolution. The dependence of the output polarization evolution on intracavity birefringence outside of the locking regions can be understood with a simple model. The locking behavior exhibits several surprising aspects and is not completely understood.

Journal ArticleDOI
TL;DR: In this article, the first laser action in a rare-earth doped chalcogenide glass fiber was reported, achieving self-pulsing behavior at 1080nm.
Abstract: We report on the first laser action in a rare-earth doped chalcogenide glass fibre. Laser action at 1080nm was obtained in a 22mm long gallium lanthanum sulphide glass fibre with a neodymium doped core, fabricated by the rod-in-tube technique. The laser was pumped continuous wave with a Ti:sapphire laser at 815nm and showed a self-pulsing behaviour.

Journal ArticleDOI
TL;DR: In this article, a perturbation formalism for the passively mode-locked stretched pulse fiber ring laser analogous to that of the fiber ring soliton laser is developed, which is applied to determine the amplitude fluctuations, carrier frequency noise, and the pulse to pulse jitter due to the amplifier spontaneous emission noise.
Abstract: A perturbation formalism is developed for the passively mode-locked stretched pulse fiber ring laser analogous to that of the fiber ring soliton laser. It is applied to determine the amplitude fluctuations, carrier frequency noise, and the pulse to pulse jitter due to the amplifier spontaneous emission noise.

Journal ArticleDOI
TL;DR: In this paper, a pulse train with a repetition rate of 115GHz was obtained at 1.55 microm from a continuous-wave modulational-instability erbium-doped fiber laser.
Abstract: A pulse train with a repetition rate of 115GHz was obtained at 1.55 microm from a continuous-wave modulational-instability erbium-doped fiber laser. This laser has a Fabry-Perot filter whose free spectral range is set at 115GHz, corresponding to the modulational-instability gain peak. This filter enables us to initiate modulational instability easily with a low threshold and produce a stable, continuous-wave pulse train. The stability of the pulse train is greatly improved by suppression of supermode noise with a combination of self-phase modulation and a narrow-band optical filter.

Journal ArticleDOI
TL;DR: A diode-pumped system for optical parametric generation of wavelength-tunable femtosecond pulses is demonstrated and saturated single-pass parametric energy conversion of 38% has been achieved with only 220 nJ of pump inside the crystal.
Abstract: A diode-pumped system for optical parametric generation of wavelength-tunable femtosecond pulses is demonstrated. It comprises an Er-doped fiber mode-locked laser, a fiber chirped-pulse amplifier, and a bulk periodically poled LiNbO3 (PPLN) optical parametric generator. The parametric generator is pumped at 777 nm with frequency-doubled microjoule pulses from the fiber amplifier and produces 300-fs pulses tunable from 1 to 3 µm with output energies up to ∼200 nJ. Use of a PPLN nonlinear crystal substantially reduces the pump energies required for efficient parametric generation. Saturated single-pass parametric energy conversion of 38% (internal) has been achieved with only 220 nJ of pump inside the crystal. A parametric generation threshold of 54 nJ is observed, and efficient parametric conversion is obtained with repetition rates up to 200 kHz.

Journal ArticleDOI
TL;DR: By applying the stretched pulse technique in a unidirectional, polarization-switch Yb(3+) fiber laser incorporating a prism-based dispersive delay line, self-start mode locking and 100-pJ pulses that can be compressed to give clean chirp-free <100-fs pulses are obtained.
Abstract: We report what we believe to be the first results on short-pulse generation in Yb3+:silica fiber. By applying the stretched pulse technique in a unidirectional, polarization-switch Yb3+ fiber laser incorporating a prism-based dispersive delay line, we obtain self-start mode locking and 100pJ pulses that can be compressed to give clean chirp-free <100fs pulses. We believe such sources to have great potential for use not only in all-solid-state high-power femtosecond pulse systems based on Yb3+:silica glass but also as seeds for conventional Nd3+:glass amplifier chains

Journal ArticleDOI
TL;DR: In this article, the authors demonstrate a diode-pumped blue laser source, consisting of a 7W diode at 807 nm that pumps a Nd:YAG laser giving 1.6 W with good beam quality at 1123 nm, and a thulium-doped upconversion fiber laser.
Abstract: We demonstrate a powerful diode-pumped blue laser source, consisting of a 7-W diode at 807 nm that pumps a Nd:YAG laser giving 1.6 W with good beam quality at 1123 nm, and a thulium-doped upconversion fiber laser. The maximum output power achieved at 481 nm is 230 mW. We also describe the behavior of a reversible loss which is generated in the fluoride fiber during high power operation.

Journal ArticleDOI
TL;DR: The unique combination of two gain media in Brillouin/erbium fiber sources results in distinctive properties of such sources as mentioned in this paper, from experimental results and a theoretical model, which is described in detail the output and efficiency properties.
Abstract: The unique combination of two gain media in Brillouin/erbium fiber lasers results in distinctive properties of such sources. The paper describes in detail the output and efficiency properties of Brillouin/erbium fiber lasers, from experimental results and a theoretical model. Single longitudinal mode output with linewidth <10 kHz was measured, with a 4-nm tuning range with the Brillouin pump wavelength. Frequency pulling associated with the Brillouin gain was investigated and observed to increase linearly with the Brillouin pump power.