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Saturable Absorber (saturable + absorber)

Distribution by Scientific Domains

Physics and Astronomy	80%
Polymers and Materials Science	14%

Selected Abstracts

Atomic-Layer Graphene as a Saturable Absorber for Ultrafast Pulsed Lasers

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2009
Qiaoliang Bao
Abstract The optical conductance of monolayer graphene is defined solely by the fine structure constant, ,,=, (where e is the electron charge, is Dirac's constant and c is the speed of light). The absorbance has been predicted to be independent of frequency. In principle, the interband optical absorption in zero-gap graphene could be saturated readily under strong excitation due to Pauli blocking. Here, use of atomic layer graphene as saturable absorber in a mode-locked fiber laser for the generation of ultrashort soliton pulses (756 fs) at the telecommunication band is demonstrated. The modulation depth can be tuned in a wide range from 66.5% to 6.2% by varying the graphene thickness. These results suggest that ultrathin graphene films are potentially useful as optical elements in fiber lasers. Graphene as a laser mode locker can have many merits such as lower saturation intensity, ultrafast recovery time, tunable modulation depth, and wideband tunability. [source]

Diode-pumped passively Q-switching mode-locked Nd:Gd0.5Y0.5VO4/V3+:YAG laser at 1.34, m

LASER PHYSICS LETTERS, Issue 11 2009
H.-T. Huang
Abstract A diode-pumped passively Q-switching mode-locked Nd:Gd0.5Y0.5VO4 laser at 1.34 , m using V3+:YAG as the saturable absorber has been demonstrated for the first time to the best of our knowledge. At the pump power of 7 W, the maximum average output power of 0.83 W and Q-switched pulse repetition rate of 140 kHz were obtained with absorber's initial transmission of 96%, with the corresponding Q-switched pulse energy estimated to be 6 , J. The duration of mode-locked pulse within Q-switched envelop was estimated to be 750 ps with 333.3 MHz repetition rate. (© 2009 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Diode-pumped doubly passively Q-switched Nd:LuVO4 laser with Cr4+:YAG saturable absorber and GaAs output coupler

LASER PHYSICS LETTERS, Issue 10 2009
K. Cheng
Abstract A diode-pumped doubly passively Q-switched Nd:LuVO4 laser with Cr4+:YAG saturable absorber and GaAs output coupler is realized. This laser can generate a shorter and more symmetric pulse profile when compared with pure GaAs. By using two Cr4+:YAG saturable absorbers with different small-signal transmissions T0 = 0.71 and T0 = 0.81, the maximum average output power are 1.15 W and 1.31 W at the incident pump power of 11.23 W, corresponding to optical conversion efficiencies of 10.2% and 11.7%. At the same incident pump power, the minimum pulse widths of 4.18 ns and 5.42 ns can be obtained at T0 = 0.71 and T0 = 0.81, respectively. The pulse repetition rate and the single-pulse peak power of the laser are also measured. (© 2009 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

All fiber Yb-Ho pulsed laser

LASER PHYSICS LETTERS, Issue 2 2009
A.S. Kurkov
Abstract For the first time we have suggested and realized passive Q-switched Yb-doped fiber laser with a saturable absorber based on Ho-doped fiber laser. The pulse duration was of 250 ns, the pulse energy , 70 , J, the peak power , 300 W. The laser is perspective for technology processes. Possible ways of laser characteristics improving are discussed. (© 2009 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Passively mode-locked fiber laser based on symmetrical nonlinear optical loop mirror

LASER PHYSICS LETTERS, Issue 5 2008
Z.X. Zhang
Abstract We propose and demonstrate a passively mode-locked Erbium-doped fiber laser based on symmetrical nonlinear optical loop mirror. The nonlinear optical loop mirror with intensitydepended transmission can act as an equivalent saturable absorber, which results in passively mode-locking of fiber laser. Pulse trains with fundamental cavity frequency and its various harmonic frequencies have been obtained. (© 2008 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Passive mode-locking with carbon nanotube saturable absorber in Nd:GdVO4 and Nd:Y0.9Gd0.1VO4 lasers operating at 1.34 ,m

LASER PHYSICS LETTERS, Issue 9 2007
S.V. Garnov
Abstract A flash-lamp pumped passively mode-locked neodymium-doped vanadate lasers operated at 1.34 ,m wavelength have been developed using a novel saturable absorber consisted of single-wall carbon nanotubes incorporated in a polymer matrix. Laser pulses with the output energy up to 50 ,J and the duration of 30 ps were generated. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Repetition rate continuously controllable passively Q-switched Nd:YAG bonded microchip laser

LASER PHYSICS LETTERS, Issue 8 2007
H. Lei
Abstract A stable repetition rate continuously controllable passively Q-switched Nd:YAG bonded microchip laser is presented. A 0.8 mm-thickness 7 mm-diameter Nd:YAG crystal at 1.6 at.% is adapted as active medium and the saturable absorber for passively Q-switched pulse generating, a 0.2 mm-thickness 6.8-mm diameter Cr4+:YAG piece was thermal bonded into the Nd:YAG after primary optical contact. By using pulse pump and controlling the duty cycle of electric pulse and temperature of laser diode, a 1 W C-mount packaged fast-collimated laser diode, we can continuously achieve repetition rate from 1 kHz to 10 kHz as active Q-switched laser. The delay time at 10 kHz is 90 ,s, while the single pulse energy is 2.8 ,J with pulse width of 2 ns. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

A c-cut Nd:GdVO4 solid-state laser passively Q-switched with Co2+:LaMgAl11O19 lasing at 1.34 µm

LASER PHYSICS LETTERS, Issue 8 2007
H.-J. Qi
Abstract We investigated a high power diode-laser pumped passively Q-switched c-cut Nd:GdVO4 solid-state laser, lasing at 1.34 µm, with a Co2+:LaMgAl11O19 saturable absorber. With the optimum output coupler transmission T = 5.5% and pump power of 11.5 W, the static output power of 3.01 W was obtained. The passively Q-switching operation with Co:LMA (initial transmission T0 = 90%) as saturable absorber, shows that the shortest output pulse width, the highest output power, the highest pulse repetition and the highest pulse peak power were 32 ns, 266 mW, 277 kHz, and 187 W, respectively. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Switchable pulses generation in passively Q-switched multilongitudinal-mode microchip laser

LASER PHYSICS LETTERS, Issue 2 2007
J. Dong
Abstract Periodical switching laser pulses with nanosecond pulse width and several kilowatts peak power from wideseparated multilongitudinal-mode oscillation were observed experimentally in laser-diode pumped passively Q-switched Yb:YAG microchip laser with Cr4+:YAG as saturable absorber. Pulses from different longitudinal modes oscillate alternatively. Periodical pulses oscillation dynamics induced by spatial hole burning effect and mode competition was investigated numerically by the evolution of the inversion population of different modes and the bleaching and recovery of the inversion population of the saturable absorber. The numerical simulations of switchable periodical pulsation of multilongitudinal-mode passively Q-switched Yb:YAG/Cr4+:YAG microchip lasers are in good agreement with experimental results and confirmed that such pulsations are an intrinsic property in passively Q-switched Yb:YAG/Cr4+:YAG microchip lasers. (© 2007 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Stimulated Raman scattering in Nd:SrWO4

LASER PHYSICS LETTERS, Issue 1 2005
H. Jelínková
Abstract Stimulated Raman scattering process in Nd:SrWO4 crystal was employed to frequency down-shift the fundamental frequency of a Nd:YAG mode-locked laser system. A single-pass configuration of Raman crystal was investigated for this purpose. After that Nd:SrWO4 laser was built and coherent pumping by alexandrite laser radiation was used. The simultaneous generation of stimulated Raman scattering was proofed for the case of Q-switching and mode-locking of Nd:SrWO4 Raman cavity. For Nd:YAG 50 ps long (1064 nm) pulsed pumping a single-pass first Stokes maximum energy and conversion efficiency were 1.6 mJ and 25% , respectively. With the free-running Nd:SrWO4 laser the maximum energy of 90 mJ at wavelength 1057 nm was obtained. Q-switching with the LiF:F,2 saturable absorber gave up to 1.3 mJ energy at the first Stokes frequency (1170 nm) in the pulse length of 3 ns. In mode-locking regime (with saturable absorber ML51 in dichlorethan or 3955 in ethanol), the total generated energy was 1.8 mJ and 2.4 mJ for ML51 and 3955 dyes, respectively. The SRS output at 1170 nm was approximately 20% of those values. (© 2005 by ASTRO, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Diode pumped 500-picosecond Nd:GdVO4 Raman laser

LASER PHYSICS LETTERS, Issue 5 2004
T. T. Basiev
Abstract Self-Raman frequency conversion in a diode-pumped passively Q-switched Nd:GdVO4 laser has been demonstrated. The use of LiF:F,2 crystal as a saturable absorber has provided effective Q-switching of the Nd:GdVO4 laser with high pulse energy. The laser pulse duration at the 1st Stokes wavelength 1174 nm was as short as 500 ps. Diode-to-Raman optical conversion efficiency more than 2 % at the pulse peak power of 9 kW was achieved. (© 2004 by ASTRO, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Tunable medium power multiwavelength fiber laser

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2009
Mansour Dastmalchi
Abstract The authors report a medium power spacing tunable multiwavelength fiber laser operating at room temperature. A double-clad erbium-ytterbium co-doped fiber was used to produce high output power. An unpumped polarization-maintaining fiber and a Lyot-Sagnac loop filter with multiple segments of polarization-maintaining fibers were used as a saturable absorber to stabilize the laser wavelengths and tunable filter to tune the separation between lasing wavelengths, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2517,2519, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24648 [source]

Characterization of highly stacked InAs quantum dot layers on InP substrate for a planar saturable absorber at 1.5 µm band

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2006
Jun Inoue
Abstract We examined the absorption saturation properties in the 1.5 µm band of novel highly stacked InAs quantum dot layers. The transmission change at vertical incidence based on the saturable absorption of the quantum dots was more than 1%. This value is as large as the reflection changes of previously reported 1-µm-band quantum dot saturable absorber with interference enhancement. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Analysis of self-pulsation characteristics of InGaN laser diode

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003
V. Z. Tronciu
Abstract Self-pulsation characteristics of InGaN laser diode emitting at 395 nm wavelength are investigated theoretically and experimentally. The laser structure consists of a multi-quantum well InGaN active layer and an InGaN single quantum well saturable absorber. Self-pulsations with the frequency range from 1.6 to 2.9 GHz have been obtained. The results show a good agreement between measured and calculated characteristics of self-pulsation. We also discuss the impact of the saturable absorber on the laser dynamics. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Nanotube,Polymer Composites for Ultrafast Photonics

ADVANCED MATERIALS, Issue 38-39 2009
Tawfique Hasan
Abstract Polymer composites are one of the most attractive near-term means to exploit the unique properties of carbon nanotubes and graphene. This is particularly true for composites aimed at electronics and photonics, where a number of promising applications have already been demonstrated. One such example is nanotube-based saturable absorbers. These can be used as all-optical switches, optical amplifier noise suppressors, or mode-lockers to generate ultrashort laser pulses. Here, we review various aspects of fabrication, characterization, device implementation and operation of nanotube-polymer composites to be used in photonic applications. We also summarize recent results on graphene-based saturable absorbers for ultrafast lasers. [source]