Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Andrey Umnikov is active.

Publication


Featured researches published by Andrey Umnikov.


Optics Letters | 2016

Bi-doped fiber amplifier with a flat gain of 25 dB operating in the wavelength band 1320–1360 nm

Naresh Kumar Thipparapu; Andrey Umnikov; Pranabesh Barua; J.K. Sahu

Bismuth (Bi)-doped phosphosilicate fibers have been fabricated by the modified chemical vapor deposition (MCVD)-solution doping technique under different process conditions. The influence of fabrication conditions on unsaturable loss in fibers has been investigated. Pump wavelength dependent Bi gain has been studied to obtain a flat gain over a wide bandwidth. A diode pumped all-fiber Bi-doped amplifier with a flat gain of 25±1  dB from 1320-1360 nm (40 nm) has been demonstrated for -10  dBm of input signal power with a noise figure (NF) ranging from 4-6 dB. Moreover, a small signal gain of 29 dB and a NF of 4.5 dB at 1340 nm has been achieved for an input signal power of -30  dBm.


Optics Letters | 2015

1120 nm diode-pumped Bi-doped fiber amplifier

Naresh Kumar Thipparapu; Saurabh Jain; Andrey Umnikov; Pranabesh Barua; J.K. Sahu

Bismuth-doped aluminosilicate fiber has been fabricated by the MCVD-solution doping method and characterized for its unsaturable loss and gain. The amplifier performance has been compared for a novel pumping wavelength of 1120 nm with the conventional pumping wavelength region of 1047 nm. Unsaturable loss was 65% and 35% at 1047 and 1120 nm, pump wavelengths, respectively. A maximum gain of about 8 dB at 1180 nm for a fiber length of 100 m was observed with 1120 nm pumping. Gain enhancement of 70% was achieved with the 1120 nm pump as compared to the 1047 nm pump. A further 3.5 dB gain was obtained on simultaneous pumping at 1047 and 1120 nm.


european quantum electronics conference | 2017

Self-mode-locked bismuth-doped fiber laser operating at 1340nm

Naresh Kumar Thipparapu; C. Guo; Andrey Umnikov; Pranabesh Barua; Austin Taranta; Shaif-ul Alam; J.K. Sahu

Bismuth (Bi)-doped fiber (BDF) lasers and amplifiers have been demonstrated in different glass hosts (i.e., aluminosilicate, phosphosilicate and germanosilicate) covering the 1150–1800nm wavelength region [1-3]. Pulsed Bi-doped fiber lasers (BDFLs) are of great interest owing to their potential applications in medicine, material processing and optical fiber communications. The first Bi-doped pulsed fiber laser was demonstrated in 2007 with 50ps pulses at 1161nm in a Bi-doped silicate fiber using SESAM as a saturable absorber (SA) [4]. A number of studies have since reported on BDFLs [3-6], however, the pulse dynamics in BDFs have not been fully understood due to the unsaturable loss and excited state absorption present in these fibers [7]. In this paper, we present an all fiber self-mode-locked BDFL operating at 1340nm with a minimum pulse width of 1.5ns, the first demonstration of its kind.


Archive | 2017

Dataset for Bismuth-doped all-fiber mode-locked laser operating at 1340 nm

Naresh Kumar Thipparapu; Chunyun Guo; Pranabesh Barua; Andrey Umnikov; Austin Taranta; J.K. Sahu

Dataset supporting: Thipparapu, N. K., Guo, C., Barua, P., Umnikov, A., Taranta, A., & Sahu, J. (2017). Bismuth-doped all-fiber mode-locked laser operating at 1340 nm. Optics Letters, 42(24).


Archive | 2017

Dataset for Self-mode-locked Bismuth-doped Fiber Laser Operating at 1340nm

Naresh Kumar Thipparapu; Guo Chunyun; Andrey Umnikov; Pranabesh Barua; Austin Taranta; Shaif-ul Alam; J.K. Sahu

Bismuth (Bi)-doped fiber (BDF) lasers and amplifiers have been demonstrated in different glass hosts (i.e., aluminosilicate, phosphosilicate and germanosilicate) covering the 1150–1800nm wavelength region [1-3]. Pulsed Bi-doped fiber lasers (BDFLs) are of great interest owing to their potential applications in medicine, material processing and optical fiber communications. The first Bi-doped pulsed fiber laser was demonstrated in 2007 with 50ps pulses at 1161nm in a Bi-doped silicate fiber using SESAM as a saturable absorber (SA) [4]. A number of studies have since reported on BDFLs [3-6], however, the pulse dynamics in BDFs have not been fully understood due to the unsaturable loss and excited state absorption present in these fibers [7]. In this paper, we present an all fiber self-mode-locked BDFL operating at 1340nm with a minimum pulse width of 1.5ns, the first demonstration of its kind.


Archive | 2016

Dataset for Bi-doped Fiber Amplifier with a Flat Gain of 25dB Operating in the Wavelength Band 1320-1360nm.

Naresh Kumar Thipparapu; Andrey Umnikov; Pranabesh Barua; J.K. Sahu

Bismuth (Bi) -doped phosphosilicate fibers have been fabricated by the modified chemical vapor deposition (MCVD) -solution doping technique under different process conditions. The influence of fabrication conditions on unsaturable loss in fibers has been investigated. Pump wavelength dependent Bi gain has been studied to obtain a flat gain over a wide bandwidth. A diode pumped all-fiber Bi-doped amplifier with a flat gain of 25 ± 1dB from 1320-1360nm (40nm) has been demonstrated for -10 dBm of input signal power with a noise figure (NF) ranging from 4–6 dB. Moreover, a small signal gain of 29 dB and a NF of 4.5dB at 1340 nm have been achieved for an input signal power of -30dBm.


Workshop on Specialty Optical Fibers and Their Applications (2015), paper WT1A.5 | 2015

Diode Pumped Bi-doped Fiber Laser Operating at 1360nm

Naresh Kumar Thipparapu; Andrey Umnikov; Saurabh Jain; Pranabesh Barua; J.K. Sahu

Bi-doped phosphosilicate fibers are fabricated by MCVD-solution doping technique under different oxidation conditions. Fibers are evaluated for unsaturable loss and laser performance. A 22mW all-fiber Bi-laser is demonstrated at 1360nm by LD pumping at 1267nm.


conference on lasers and electro optics | 2018

Yb-doped Large-Mode-Area Al-P-Silicate Laser Fiber fabricated by MCVD

A. Halder; Di Lin; Andrey Umnikov; N.J. Ramirez-Martinez; M. Núñez-Velázquez; Pranabesh Barua; Shaif-ul Alam; J.K. Sahu


conference on lasers and electro optics | 2018

Novel Fabrication Technique for Highly Efficient Tm-doped Fibers

N.J. Ramirez-Martinez; M. Núñez-Velázquez; Andrey Umnikov; J.K. Sahu


Advanced Photonics 2018 (BGPP, IPR, NP, NOMA, Sensors, Networks, SPPCom, SOF) | 2018

Efficient Thulium-doped Fiber Laser Operating in the 1890 – 2080nm Wavelength Band

N.J. Ramirez-Martinez; M. Núñez-Velázquez; Andrey Umnikov; J.K. Sahu

Collaboration


Dive into the Andrey Umnikov's collaboration.

Top Co-Authors

Avatar

J.K. Sahu

University of Southampton

View shared research outputs
Top Co-Authors

Avatar

Pranabesh Barua

University of Southampton

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Austin Taranta

University of Southampton

View shared research outputs
Top Co-Authors

Avatar

Saurabh Jain

University of Southampton

View shared research outputs
Top Co-Authors

Avatar

Shaif-ul Alam

University of Southampton

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

C. Guo

University of Southampton

View shared research outputs
Researchain Logo
Decentralizing Knowledge