Sergey Semjonov | Prokhorov General Physics Institute (original) (raw)

Uploads

Papers by Sergey Semjonov

Journal of Lightwave Technology, 1991

Characteristics of the continuous wave fiber laser based on a high-concentration Er-doped phospha... more Characteristics of the continuous wave fiber laser based on a high-concentration Er-doped phosphate core silica cladding fiber were investigated. The laser demonstrated a maximum output power about 105 mW at 1535 nm with a fiber length of only 15 cm. The slope efficiency was about 25.5 %.

HAL (Le Centre pour la Communication Scientifique Directe), Sep 17, 2007

In During the las been deployed to increase the output power of fibre lasers, now as high as few ... more In During the las been deployed to increase the output power of fibre lasers, now as high as few kW in cw-regime [1]. At such considerable powers threshold of nonlinear effects (mainly stimulated scatterings) can be easily reached and significantly disturb spectral and spatial properties ...

Results in physics, Mar 1, 2020

Proceedings of SPIE, Apr 25, 2008

Although singlemode fiber lasers become a mature technology, enhancements, in terms of output pow... more Although singlemode fiber lasers become a mature technology, enhancements, in terms of output power, spatial beam quality, bend insensitivity are still required. A major trend is to increase the active core area to increase the thresholds of nonlinear effects while ensuring a transverse singlemode behavior. Actually, increasing the active ions' concentration is also demanded since it allows a drastic reduction

Proceedings of SPIE, Nov 18, 1993

Factors limiting the maximum strength of carbon coated fibers are considered. The ultimate inert ... more Factors limiting the maximum strength of carbon coated fibers are considered. The ultimate inert strength of carbon coated fibers was estimated by using the strength reduction data at high temperature.

This paper show that an all-solid photonic band-gap fiber (PBGF) with a large mode area offers in... more This paper show that an all-solid photonic band-gap fiber (PBGF) with a large mode area offers interesting new options for the compression of high-peak power laser pulses. Even in the class of large-mode-area fibers, dispersion of PBGFs can be efficiently tailored by tuning photonic band gaps of the fiber cladding. The fiber provides a low-loss transmission within the fundamental photonic band gap of its cladding from approximately 930 to 1300 nm. Laser pulses experienced a significant spectral broadening as a result of nonlinear-optical processes inside the fiber, with the spectrum of light pulses transmitted through fiber covering, roughly, the entire transmission band of the PBGF. Spectral-temporal maps of ultrashort light pulses were measured by cross-correlation frequency resolved optical gating (XFROG) with a 800-nm, 70-fs output of a solid laser used as a reference pulse. A typical XFROG trace of a laser pulse transmitted through a 22-cm piece of PBGF, suggests that group velocity dispersion of the PBGF vanishes at approximately 1200 nm and indicates that a chirp acquired by the light pulse at the fiber output is mainly due to the normal dispersion of the fiber. With a prism compressor designed to compensate for this chirp, light pulses with a pulse width of about 60 fs and an energy of 0.35 muJ were produced. XFROG traces of compressed pulses suggest that even shorter pulse widths can be achieved with an accurate compensation of high-order phase shifts.

Polymer Science Series B, 2020

Proceedings of SPIE, Mar 1, 1994

At temperatures higher than 400 degree(s)C the decrease of aluminum coated fiber strength due to ... more At temperatures higher than 400 degree(s)C the decrease of aluminum coated fiber strength due to interaction between glass and aluminum was observed. The rate of this decrease appears to depend on the interface between glass and metal. The influence of atmosphere above the metallizer at the application of a metal coating by the freezing method was investigated. Some decrease of the initial bending strength, yet longer lifetime at high temperatures, have been observed for fibers sealed in atmosphere containing oxygen, which can create an alumina layer between silica glass and aluminum. In order to exclude the chemical reaction between silica and aluminum, an intermediate layer of carbon was applied during the fiber drawing. Results of the carbon coating influence on strength and lifetime of aluminum coated fibers at high temperatures are presented.

Inorganic Materials, Mar 1, 2007

We have studied the effect of drawing conditions and process environment on the mechanical streng... more We have studied the effect of drawing conditions and process environment on the mechanical strength of microstructured optical fibers. The results indicate that, even at reduced drawing temperatures, high-strength fibers with few “weak” points can be produced provided that the walls of the holes in the preform are sufficiently clean. The effects of air humidity and different liquids in the holes on the strength of microstructured fibers are shown to be similar to those for standard fibers.

Proceedings of SPIE, Feb 2, 2001

Proceedings of SPIE, Apr 16, 2001

Proceedings of SPIE, May 17, 2000

A technology has been developed for fabrication of single- mode fibers with a high level of phosp... more A technology has been developed for fabrication of single- mode fibers with a high level of phosphorous doping (10 - 17 mol% P2O5) in the core. Characteristics of such fibers intended for use in Raman lasers operating at 1.24 and 1.48 micrometers are investigated. A reduction of fiber drawing temperature and additional doping of the fiber core with fluorine allowed a reduction of optical losses below 1 dB/km in wavelength range 1.1 - 1.5 micrometers .

Optics & Photonics News, Jun 1, 1999

Сборник трудов конференции «International Conference on Advanced Laser Technologies (ALT)», 2019

Quantum Electronics, Dec 1, 2021

All-glass microstructured optical fibres (MOFs) with a core 20 μm in diameter and two rings of ci... more All-glass microstructured optical fibres (MOFs) with a core 20 μm in diameter and two rings of circular fluorine-doped silica glass elements with a reduced refractive index, different diameters, and different distances between them are theoretically studied. The properties of these MOFs are numerically analysed using the finite element method. The leakage losses for the fundamental and higher-order modes in the spectral range 0.75−1.65 μm are calculated for straight and bent MOFs. It is shown that the considered MOF design allows single-mode operation in the range 0.98−1.26 μm at a bending radius of down to 0.08 m, the leakage losses for the bent MOF at a wavelength of 1.05 μm being 0.046 dB m−1.

Quantum Electronics, Nov 29, 2016

Quantum Electronics, Jun 30, 2018

Journal of Lightwave Technology, 1991

Characteristics of the continuous wave fiber laser based on a high-concentration Er-doped phospha... more Characteristics of the continuous wave fiber laser based on a high-concentration Er-doped phosphate core silica cladding fiber were investigated. The laser demonstrated a maximum output power about 105 mW at 1535 nm with a fiber length of only 15 cm. The slope efficiency was about 25.5 %.

HAL (Le Centre pour la Communication Scientifique Directe), Sep 17, 2007

In During the las been deployed to increase the output power of fibre lasers, now as high as few ... more In During the las been deployed to increase the output power of fibre lasers, now as high as few kW in cw-regime [1]. At such considerable powers threshold of nonlinear effects (mainly stimulated scatterings) can be easily reached and significantly disturb spectral and spatial properties ...

Results in physics, Mar 1, 2020

Proceedings of SPIE, Apr 25, 2008

Although singlemode fiber lasers become a mature technology, enhancements, in terms of output pow... more Although singlemode fiber lasers become a mature technology, enhancements, in terms of output power, spatial beam quality, bend insensitivity are still required. A major trend is to increase the active core area to increase the thresholds of nonlinear effects while ensuring a transverse singlemode behavior. Actually, increasing the active ions' concentration is also demanded since it allows a drastic reduction

Proceedings of SPIE, Nov 18, 1993

Factors limiting the maximum strength of carbon coated fibers are considered. The ultimate inert ... more Factors limiting the maximum strength of carbon coated fibers are considered. The ultimate inert strength of carbon coated fibers was estimated by using the strength reduction data at high temperature.

This paper show that an all-solid photonic band-gap fiber (PBGF) with a large mode area offers in... more This paper show that an all-solid photonic band-gap fiber (PBGF) with a large mode area offers interesting new options for the compression of high-peak power laser pulses. Even in the class of large-mode-area fibers, dispersion of PBGFs can be efficiently tailored by tuning photonic band gaps of the fiber cladding. The fiber provides a low-loss transmission within the fundamental photonic band gap of its cladding from approximately 930 to 1300 nm. Laser pulses experienced a significant spectral broadening as a result of nonlinear-optical processes inside the fiber, with the spectrum of light pulses transmitted through fiber covering, roughly, the entire transmission band of the PBGF. Spectral-temporal maps of ultrashort light pulses were measured by cross-correlation frequency resolved optical gating (XFROG) with a 800-nm, 70-fs output of a solid laser used as a reference pulse. A typical XFROG trace of a laser pulse transmitted through a 22-cm piece of PBGF, suggests that group velocity dispersion of the PBGF vanishes at approximately 1200 nm and indicates that a chirp acquired by the light pulse at the fiber output is mainly due to the normal dispersion of the fiber. With a prism compressor designed to compensate for this chirp, light pulses with a pulse width of about 60 fs and an energy of 0.35 muJ were produced. XFROG traces of compressed pulses suggest that even shorter pulse widths can be achieved with an accurate compensation of high-order phase shifts.

Polymer Science Series B, 2020

Proceedings of SPIE, Mar 1, 1994

At temperatures higher than 400 degree(s)C the decrease of aluminum coated fiber strength due to ... more At temperatures higher than 400 degree(s)C the decrease of aluminum coated fiber strength due to interaction between glass and aluminum was observed. The rate of this decrease appears to depend on the interface between glass and metal. The influence of atmosphere above the metallizer at the application of a metal coating by the freezing method was investigated. Some decrease of the initial bending strength, yet longer lifetime at high temperatures, have been observed for fibers sealed in atmosphere containing oxygen, which can create an alumina layer between silica glass and aluminum. In order to exclude the chemical reaction between silica and aluminum, an intermediate layer of carbon was applied during the fiber drawing. Results of the carbon coating influence on strength and lifetime of aluminum coated fibers at high temperatures are presented.

Inorganic Materials, Mar 1, 2007

We have studied the effect of drawing conditions and process environment on the mechanical streng... more We have studied the effect of drawing conditions and process environment on the mechanical strength of microstructured optical fibers. The results indicate that, even at reduced drawing temperatures, high-strength fibers with few “weak” points can be produced provided that the walls of the holes in the preform are sufficiently clean. The effects of air humidity and different liquids in the holes on the strength of microstructured fibers are shown to be similar to those for standard fibers.

Proceedings of SPIE, Feb 2, 2001

Proceedings of SPIE, Apr 16, 2001

Proceedings of SPIE, May 17, 2000

A technology has been developed for fabrication of single- mode fibers with a high level of phosp... more A technology has been developed for fabrication of single- mode fibers with a high level of phosphorous doping (10 - 17 mol% P2O5) in the core. Characteristics of such fibers intended for use in Raman lasers operating at 1.24 and 1.48 micrometers are investigated. A reduction of fiber drawing temperature and additional doping of the fiber core with fluorine allowed a reduction of optical losses below 1 dB/km in wavelength range 1.1 - 1.5 micrometers .

Optics & Photonics News, Jun 1, 1999

Сборник трудов конференции «International Conference on Advanced Laser Technologies (ALT)», 2019

Quantum Electronics, Dec 1, 2021

All-glass microstructured optical fibres (MOFs) with a core 20 μm in diameter and two rings of ci... more All-glass microstructured optical fibres (MOFs) with a core 20 μm in diameter and two rings of circular fluorine-doped silica glass elements with a reduced refractive index, different diameters, and different distances between them are theoretically studied. The properties of these MOFs are numerically analysed using the finite element method. The leakage losses for the fundamental and higher-order modes in the spectral range 0.75−1.65 μm are calculated for straight and bent MOFs. It is shown that the considered MOF design allows single-mode operation in the range 0.98−1.26 μm at a bending radius of down to 0.08 m, the leakage losses for the bent MOF at a wavelength of 1.05 μm being 0.046 dB m−1.

Quantum Electronics, Nov 29, 2016

Quantum Electronics, Jun 30, 2018