Search results for "erbium"

Wavelength-codified fiber laser hydrogen detector

2005

We report a scheme for an optical hydrogen detector that codifies the information in wavelength. The system is based on an erbium-doped fiber laser with two coupled cavities and a Palladium-coated tapered fiber within one of the laser cavities. The tapered fiber acts as the hydrogen-sensing element. When the sensing element is exposed to a hydrogen atmosphere, its attenuation decreases changing the cavity losses. This change leads the system to switch lasing from the wavelength of the auxiliary cavity to the characteristic wavelength of the cavity which contains the sensing element. The detection level can be shifted by adjusting the reflective elements of the cavity containing the sensing …

A Theoretical Approach to the Risken-Nummedal Instability in Erbium-Doped Fibre Lasers

2005

Radiation hardening techniques for rare-earth-based optical fibers and amplifiers

2012

Er/Yb doped fibers and amplifiers have been shown to be very radiation sensitive, limiting their integration in space. We present an approach including successive hardening techniques to enhance their radiation tolerance. The efficiency of our approach is demonstrated by comparing the radiation responses of optical amplifiers made with same lengths of different rare-earth doped fibers and exposed to gamma-rays. Previous studies indicated that such amplifiers suffered significant degradation for doses exceeding 10 krad. Applying our techniques significantly enhances the amplifier radiation resistance, resulting in a very limited degradation up to 50 krad. Our optimization techniques concern …

Highly-chirped similaritons generation from a mode-locked fiber laser

2007

In this communication, we report experimental and numerical results on dynamics and propagation of self-similar pulses in a passively mode-locked ytterbium doped DC fiber laser.

Erbium doped optical fiber lasers for magnetic field sensing

2015

In this work two erbium doped optical fiber laser configurations for magnetic field measurement are implemented and compared. The first laser is set-up in a loop configuration and requires only a single FBG (Fiber Bragg Grating), acting as mirror. A second laser employs a simpler linear cavity configuration but requires two FBGs with spectral overlap to form the laser cavity. A bulk magnetostrictive material made of Terfenol-D is attached to the laser FBGs enabling modulation of its operation wavelength by the magnetic field. Moreover, a passive interferometer was developed to demodulate the AC magnetic field information where the corresponding demodulation algorithms were software based. B…

Excited-state absorption in erbium-doped silica fiber with simultaneous excitation at 977 and 1531 nm

2009

We report a study of the excited-state absorption (ESA) in erbium-doped silica fiber (EDF) pumped at 977 nm, when the fiber is simultaneously excited by signal radiation at 1531 nm. We show, both experimentally and theoretically, that ESA efficiency at 977 nm gets strongly enhanced only in the presence of signal power. Experimentally, this conclusion is supported through the detection of upconversion emission, a “fingerprint” of the ESA process, and through the measurements of the EDF nonlinear transmission coefficient for the pump wavelength, which is sensitive to the ESA value. It is shown that the experimental data are precisely modeled with an advanced five-level Er3+ model developed fo…

Observation of dark dot splitting pattern in terbium gallium garnet

1999

We have observed a new polarisation pattern in terbium gallium garnet which is both laser excited and mechanically stressed. The pattern can be characterized by a splitting from a “one dot” structure to a “two dots” structure. We have found that the new pattern is very sensitive to the orientation and the strength of the external forces applied to the sample. Thanks to this sensitivity and to the image simplicity, this new effect may be used in a vectorial force sensor and actuator.

Dynamic Bragg gratings induced in erbium-doped fiber at phase-Modulated beams' coupling

2005

We present the results of an experimental study of dynamic amplitude and phase Bragg gratings induced in a heavy-doped erbium fiber at the wavelengths 1532 and 1538 nm under the 980-nm pumping. The technique of two phase-modulated beams' coupling was applied for an experimental measurement of the changes in refractive index and gain accompanying the gratings' formation in the fiber, and an analysis based on the Kramers-Kronig Relations for the fiber absorption/gain spectra and two-pass amplifying was performed for modeling these changes.

Phacoemulsification and Vitrectomy with the Erbium: or Neodymium:YAG-Laser

2002

Summary There are an increasing number of applications for Erbium:YAG and Neodymium:YAG lasers in opthalmology. Laser phacoemulsification and Erbium-laser vitrectomy are of major interest. We report the underlying technology and more than 1-year-experience using the PHACOLASE (Carl Zeiss Meditec, Jena, Germany, 10–100 Hz frequency, 5–50 mJ single pulse energy) for phacoemulsification and pars plana vitrectomy and the Lyla-Dodick laser photolysis (A.R.C. Laser, Eckental-Forth, Germany, 1–20 Hz, up to 8 mJ single pulse energy). The Erbium:YAG laser and Neodymium:YAG laser enabled us to extract lenses with up to medium hard nuclei. Moreover, the Erbium laser enabled fast vitrectomy with little…

Temperature and impurity concentration effects on upconversion luminescence in LaInO3 doped with Er3+

2016

In this paper a novel method for synthesis of LaInO3:Er3+ is reported and upconversion luminescence properties of the synthesized material at different temperatures (9–300 K) are studied. The samples were prepared by co-precipitation and subsequent heat treatment of lanthanum, indium and erbium hydroxides. It is shown that the excitation at 980 nm leads to a strong green upconversion luminescence in the material. At the concentrations above 0.1 mol. % of Er3+ the energy transfer upconversion mechanism of the luminescence becomes evident. Further increase of Er3+ content in the material leads to higher red-to-green upconversion luminescence intensity ratio. The mechanisms responsible for the…