The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Markus Pollnau - One of the best experts on this subject based on the ideXlab platform.
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Rare-Earth-Ion-Doped Channel Waveguide Lasers on Silicon
IEEE Journal of Selected Topics in Quantum Electronics, 2015Co-Authors: Markus PollnauAbstract:This paper reviews the recent developments in rare-earth-ion-doped Channel Waveguide lasers. Optical gain in rare-earth-ion-doped Waveguides has been increased by two orders of magnitude to similar to 1000 dB/cm and Waveguide lasers with extremely high slope efficiencies and output powers exceeding the Watt level have been demonstrated. Of particular interest in integrated optics is the recent integration of rare-earth-ion-doped Channel Waveguide lasers in amorphous materials directly deposited on a silicon substrate. Remarkable performance with respect to slope efficiency, output power, and laser linewidth has been achieved.
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thulium Channel Waveguide laser with 1 6 w of output power and 80 slope efficiency
Optics Letters, 2014Co-Authors: K Van Dalfsen, S Aravazhi, C. Grivas, Sonia M Garciablanco, Markus PollnauAbstract:Laser experiments were performed on buried, ridge-type Channel Waveguides in 8 at.% thulium-doped, yttrium– gadolinium–lutetium co-doped potassium double tungstate. By pumping with a Ti:sapphire laser at 794 nm, 1.6 W of output power at 1.84 μm with a maximum slope efficiency of ∼80% was obtained in a laser resonator with a high output-coupling degree of 89%. To the best of our knowledge, this result represents the most efficient 2-μm Channel Waveguide laser to date.
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highly efficient yb 3 doped Channel Waveguide laser at 981 nm
Optics Express, 2013Co-Authors: Dimitri Geskus, Edward H. Bernhardi, K Van Dalfsen, S Aravazhi, Markus PollnauAbstract:Channel Waveguide lasers operating at 981 nm are demonstrated in KY1−x−yGdxLuy(WO4)2:Yb3+ Waveguides grown by liquid phase epitaxy onto undoped KY(WO4)2 substrates and microstructured by Ar+ beam etching. Under pumping at 934 nm of samples with different Waveguide geometry and outcoupling degree, a record-high slope efficiency of 76% versus absorbed pump power and a record-high output power of 650 mW for rare-earth-ion-doped microstructured Channel Waveguide lasers is achieved. The laser performance is compared to that of the same devices when pumping at 981 nm and lasing near 1025 nm.
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engineering lattice matching doping level and optical properties of ky wo4 2 gd lu yb layers for a cladding side pumped Channel Waveguide laser
Applied Physics B, 2013Co-Authors: S Aravazhi, Uwe Griebner, Dimitri Geskus, K Van Dalfsen, C. Grivas, Sonia M Garciablanco, Sergio A Vazquezcordova, Markus PollnauAbstract:Single-crystalline KY1-x-y-zGdxLuyYbz(WO4)2 layers are grown onto undoped KY(WO4)2 substrates by liquid-phase epitaxy. The purpose of co-doping the KY(WO4)2 layer with suitable fractions of Gd3+ and Lu3+ is to achieve lattice-matched layers that allow us to engineer a high refractive-index contrast between waveguiding layer and substrate for obtaining tight optical mode confinement and simultaneously accommodate a large range of Yb3+ doping concentrations by replacing Lu3+ ions of similar ionic radius for a variety of optical amplifier or laser applications. Crack-free layers, up to a maximum lattice mismatch of ~0.08 %, are grown with systematic variations of Y3+, Gd3+, Lu3+, and Yb3+ concentrations, their refractive indices are measured at several wavelengths, and Sellmeier dispersion curves are derived. The influence of co-doping on the spectroscopy of Yb3+ is investigated. As evidenced by the experimental results, the lattice constants, refractive indices, and transition cross-sections of Yb3+ in these co-doped layers can be approximated with good accuracy by weighted averages of data from the pure compounds. The obtained information is exploited to fabricate a twofold refractive-index-engineered sample consisting of a highly Yb3+-doped tapered Channel Waveguide embedded in a passive planar Waveguide, and a cladding-side-pumped Channel Waveguide laser is demonstrated.
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thulium Channel Waveguide laser in a monoclinic double tungstate with 70 slope efficiency
Optics Letters, 2012Co-Authors: K Van Dalfsen, S Aravazhi, C. Grivas, Sonia M Garciablanco, Markus PollnauAbstract:Laser experiments were performed on buried, ridge-type Channel Waveguides in an 8 at. % thulium-doped, yttrium-gadolinium-lutetium codoped monoclinic double tungstate. A maximum slope efficiency of 70% and output powers up to 300 mW about 2.0 μm were obtained in a mirrorless laser resonator, by pumping with a Ti:sapphire laser near 800 nm. To the best of our knowledge, this result represents the most efficient 2 μm Channel Waveguide laser to date. Lasing is obtained at various wavelengths between 1810 nm and 2037 nm.
Thomas Calmano - One of the best experts on this subject based on the ideXlab platform.
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2 ghz carbon nanotube mode locked yb yag Channel Waveguide laser
Optics Express, 2018Co-Authors: Sun Young Choi, Thomas Calmano, Fabian Rotermund, Christian KrankelAbstract:We demonstrate GHz-repetition rate mode-locked operation of a femtosecond-laser-inscribed Yb:YAG Channel Waveguide laser using single-walled carbon nanotube saturable absorber mirror (SWCNT-SAM). A 6.3-mm-long, type II Yb:YAG Waveguide laser with an extended cavity configuration delivers mode-locked picosecond (ps) pulses at GHz repetition rates. The dispersion of the laser cavity is compensated by the combination of a multi-functional output coupler and the Gires-Tournois interferometer (GTI) effect arising from an air-gap between the facet of the Waveguide and the output coupler. The incident beam fluence on the SWNCNT-SAM is controlled by adjusting two intracavity lenses to avoid optical damage on the polymer nanocomposite matrix containing the SWCNTs. The average output power of our mode-locked Waveguide laser is 322 mW at a pump power of 3.2 W. Nearly Fourier-limited, stable 2-ps-short pulses are generated at a repetition rate of 2.08 GHz.
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highly efficient q switched yb yag Channel Waveguide laser with 5 6 w of average output power
Optics Letters, 2016Co-Authors: Sargis Hakobyan, Valentin J Wittwer, Kore Hasse, Christian Krankel, Thomas Sudmeyer, Thomas CalmanoAbstract:In this Letter, we present high-power continuous wave (CW) and Q-switched femtosecond laser-written Yb:YAG Channel Waveguide lasers. In Q-switched operation, obtained by a semiconductor saturable absorber mirror (SESAM), as well as in CW operation, the laser generates average output powers of more than 5.6 W and reaches slope efficiencies above 74%. The Q-switched laser operated at a maximum repetition rate of 5.4 MHz with a minimum pulse duration of 11 ns, and with a maximum pulse energy of 1 μJ. This laser has almost an order of magnitude higher average output power than previously reported Q-switched Channel Waveguide lasers.
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q switched operation of a femtosecond laser inscribed yb yag Channel Waveguide laser using carbon nanotubes
Optics Express, 2015Co-Authors: Christian Krankel, Thomas Calmano, Gunter Huber, Sun Young Choi, Fabian Rotermund, Mi Hye Kim, Dongil YeomAbstract:We demonstrate a diode-pumped femtosecond-laser-inscribed Yb:YAG Channel Waveguide laser, Q-switched by using single-walled carbon nanotubes (SWCNTs) near 1029 nm. We used saturable absorber mirrors (SAMs) fabricated by depositing SWCNTs on three different output couplers. Best performance of the 9.3-mm-long ultra-compact Q-switched Waveguide laser is obtained with an output coupling transmission of 20%. In this case, a maximum average output power of 60 mW with a corresponding pulse energy of 37.7 nJ and a pulse duration of 88 ns at 1.59-MHz repetition rate were achieved. The highest pulse energy of 39.2 nJ and the shortest pulse duration of 78 ns were obtained with 30% and 10% output couplers, respectively.
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highly efficient yb yag Channel Waveguide laser written with a femtosecond laser
Optics Express, 2010Co-Authors: Jorg Siebenmorgen, Thomas Calmano, K Petermann, Gunter HuberAbstract:Using a femtosecond Ti:Sapphire laser, micro-tracks of material damage were written into Yb:YAG crystals. Waveguiding was achieved in a Channel between pairs of tracks with guiding losses of 1.3 dB/cm at a wavelength of 1063 nm, due to a stress induced change of the refractive index. Pumped at a wavelength of 941 nm, highly efficient laser oscillation in a Yb:YAG Channel Waveguide at a wavelength of 1030 nm was demonstrated. An output power of 0.8 W at 1.2 W of launched pump power was achieved, resulting in a record slope efficiency of 75%.
A K Kar - One of the best experts on this subject based on the ideXlab platform.
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q switched nd yag Channel Waveguide laser through evanescent field interaction with surface coated graphene
Applied Physics Letters, 2014Co-Authors: Yang Tan, John R. Macdonald, A K Kar, Feng ChenAbstract:We demonstrate a compact passively Q-switched Channel Waveguide laser based on the interaction of the evanescent-field and the graphene coated surface. The graphene layer is transferred onto the surface of a femtosecond laser inscribed Nd:YAG surface Waveguide for a simple integration of the saturable absorber and Waveguide structure. The passive Q-switching configuration is based on the evanescent-field interaction with graphene. A 1064 nm pulsed Waveguide laser with a maximum repetition rate of 10.4 MHz has been achieved, reaching an output power of 48 mW. The shortest pulse duration of the Channel Waveguide laser is 52 ns.
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compact cr zns Channel Waveguide laser operating at 2333 nm
Optics Express, 2014Co-Authors: John R. Macdonald, Kenneth L. Schepler, Patrick A. Berry, Stephen J. Beecher, Adam Lancaster, S B Mirov, A K KarAbstract:A compact mid-infrared Channel Waveguide laser is demonstrated in Cr:ZnS with a view to power scaling chromium laser technology utilizing the thermo-mechanical advantages of Cr:ZnS over alternative transition metal doped II-VI semiconductor laser materials. The laser provided a maximum power of 101 mW of CW output at 2333 nm limited only by the available pump power. A maximum slope efficiency of 20% was demonstrated.
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efficient mid infrared cr znse Channel Waveguide laser operating at 2486 nm
Optics Letters, 2013Co-Authors: John R. Macdonald, Kenneth L. Schepler, Patrick A. Berry, Stephen J. Beecher, G Brown, A K KarAbstract:We report a Cr:ZnSe Channel Waveguide laser operating at 2486 nm. A maximum power output of 285 mW is achieved and slope efficiencies as high as 45% are demonstrated. Ultrafast laser inscription is used to fabricate the depressed cladding Waveguide in a polycrystalline Cr:ZnSe sample. Waveguide structures are proposed as a compact and robust solution to the thermal lensing problem that has so far limited power scaling of transition metal doped II-VI lasers.
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70 slope efficiency from an ultrafast laser written nd gdvo4 Channel Waveguide laser
Optics Express, 2010Co-Authors: Yang Tan, A K Kar, Feng Chen, Airan Rodenas, Robert R Thomson, D JaqueAbstract:We report high efficiency continuous wave laser oscillations at 1063.6 nm from an ultrafast laser written Nd3+:GdVO4 Channel Waveguide under the 808 nm optical excitation. A record 17 mm·s−1 writing speed was used while the low propagation loss of the Waveguide (~0.5 dB·cm−1) enabled laser performance with a threshold pump power as low as 52 mW and a near to quantum defect limited laser slope efficiency of 70%.
Feng Chen - One of the best experts on this subject based on the ideXlab platform.
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q switched nd yag Channel Waveguide laser through evanescent field interaction with surface coated graphene
Applied Physics Letters, 2014Co-Authors: Yang Tan, John R. Macdonald, A K Kar, Feng ChenAbstract:We demonstrate a compact passively Q-switched Channel Waveguide laser based on the interaction of the evanescent-field and the graphene coated surface. The graphene layer is transferred onto the surface of a femtosecond laser inscribed Nd:YAG surface Waveguide for a simple integration of the saturable absorber and Waveguide structure. The passive Q-switching configuration is based on the evanescent-field interaction with graphene. A 1064 nm pulsed Waveguide laser with a maximum repetition rate of 10.4 MHz has been achieved, reaching an output power of 48 mW. The shortest pulse duration of the Channel Waveguide laser is 52 ns.
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guided continuous wave and graphene based q switched lasers in carbon ion irradiated nd yag ceramic Channel Waveguide
Optics Express, 2014Co-Authors: Shavkat Akhmadaliev, Shengqiang Zhou, Feng ChenAbstract:We demonstrate the lasing performance in the Nd:YAG ceramic Channel Waveguide produced by the carbon ion irradiation, including the continuous-wave (cw) and graphene Q-switched configurations. The highest slope efficiency of 56% and the lowest threshold of 40 mW have been obtained for the cw Waveguide laser. With graphene as a saturable absorber, the Q-switched laser produces stable pulses with 57 ns pulse duration and 77 nJ pulse energy, respectively. Under the variation of the pumping power, the repetition of the pulse laser could be modified from 1.5 MHz to 4.1 MHz.
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Channel Waveguide lasers in Nd:LGS crystals
Optics express, 2013Co-Authors: Yingying Ren, Feng Chen, Javier R. Vázquez De Aldana, Huaijin ZhangAbstract:Optical Channel Waveguides have been produced in Nd:LGS laser crystals by using ultrafast laser inscription with a depressed cladding configuration. The cross sectional shape of the cladding Waveguides is circular, surrounded by low refractive index tracks, which makes the Channel Waveguides as three-dimensional tubular structures. Under optical pump of 810 nm light, continuous-wave Waveguide lasers at 1068 nm have been achieved at room temperature, with minimum lasing threshold of 54 mW, a maximum slope efficiency of 24% and a maximum output power of 16 mW.
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continuous wave nd yag Channel Waveguide laser produced by focused proton beam writing
Optics Express, 2010Co-Authors: Yicun Yao, Yang Tan, Feng Chen, Ningning Dong, A A BettiolAbstract:We report on mirrorless continuous wave laser oscillation at 1064 nm from a 808 nm pumped Nd:YAG optical Channel Waveguide fabricated by 1 MeV focused proton beam writing. Pump power threshold has been found to be 94 mW with a laser slope efficiency of 40%. A maximum output power at 1064 nm for the Waveguide laser is 63 mW at absorbed pump power of 247 mW.
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70 slope efficiency from an ultrafast laser written nd gdvo4 Channel Waveguide laser
Optics Express, 2010Co-Authors: Yang Tan, A K Kar, Feng Chen, Airan Rodenas, Robert R Thomson, D JaqueAbstract:We report high efficiency continuous wave laser oscillations at 1063.6 nm from an ultrafast laser written Nd3+:GdVO4 Channel Waveguide under the 808 nm optical excitation. A record 17 mm·s−1 writing speed was used while the low propagation loss of the Waveguide (~0.5 dB·cm−1) enabled laser performance with a threshold pump power as low as 52 mW and a near to quantum defect limited laser slope efficiency of 70%.
John R. Macdonald - One of the best experts on this subject based on the ideXlab platform.
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q switched nd yag Channel Waveguide laser through evanescent field interaction with surface coated graphene
Applied Physics Letters, 2014Co-Authors: Yang Tan, John R. Macdonald, A K Kar, Feng ChenAbstract:We demonstrate a compact passively Q-switched Channel Waveguide laser based on the interaction of the evanescent-field and the graphene coated surface. The graphene layer is transferred onto the surface of a femtosecond laser inscribed Nd:YAG surface Waveguide for a simple integration of the saturable absorber and Waveguide structure. The passive Q-switching configuration is based on the evanescent-field interaction with graphene. A 1064 nm pulsed Waveguide laser with a maximum repetition rate of 10.4 MHz has been achieved, reaching an output power of 48 mW. The shortest pulse duration of the Channel Waveguide laser is 52 ns.
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compact cr zns Channel Waveguide laser operating at 2333 nm
Optics Express, 2014Co-Authors: John R. Macdonald, Kenneth L. Schepler, Patrick A. Berry, Stephen J. Beecher, Adam Lancaster, S B Mirov, A K KarAbstract:A compact mid-infrared Channel Waveguide laser is demonstrated in Cr:ZnS with a view to power scaling chromium laser technology utilizing the thermo-mechanical advantages of Cr:ZnS over alternative transition metal doped II-VI semiconductor laser materials. The laser provided a maximum power of 101 mW of CW output at 2333 nm limited only by the available pump power. A maximum slope efficiency of 20% was demonstrated.
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Laser-Inscribed Cr:ZnSe Channel Waveguide Lasers
Advanced Solid-State Lasers Congress, 2013Co-Authors: Patrick A. Berry, Sean A. Mcdaniel, Stephen J. Beecher, John R. Macdonald, Kenneth L. ScheplerAbstract:We report the characterization of Cr:ZnSe Channel Waveguide lasers with Watt-level outputs. Waveguides are fabricated via ultrafast laser inscription in polycrystalline Cr:ZnSe samples. The effect of Waveguide structure and fabrication on laser performance is investigated.
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efficient mid infrared cr znse Channel Waveguide laser operating at 2486 nm
Optics Letters, 2013Co-Authors: John R. Macdonald, Kenneth L. Schepler, Patrick A. Berry, Stephen J. Beecher, G Brown, A K KarAbstract:We report a Cr:ZnSe Channel Waveguide laser operating at 2486 nm. A maximum power output of 285 mW is achieved and slope efficiencies as high as 45% are demonstrated. Ultrafast laser inscription is used to fabricate the depressed cladding Waveguide in a polycrystalline Cr:ZnSe sample. Waveguide structures are proposed as a compact and robust solution to the thermal lensing problem that has so far limited power scaling of transition metal doped II-VI lasers.
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Compact mid-infrared Cr:ZnSe Channel Waveguide laser
Applied Physics Letters, 2013Co-Authors: John R. Macdonald, Kenneth L. Schepler, Patrick A. Berry, Stephen J. Beecher, Ajoy K. KarAbstract:We demonstrate a mid-infrared Channel Waveguide laser in Cr:ZnSe operating at 2573 nm. The compact cavity has a total footprint of less than 3 cm2 and produces a maximum power output of 18.5 mW. The depressed index cladding structures guide across the entire emission band of Cr:ZnSe, from 1.9 μm to 3.4 μm, indicating the viability of the device for integrated and robust continuously tunable mid-infrared sources.