The Experts below are selected from a list of 15075 Experts worldwide ranked by ideXlab platform
Götz Erbert - One of the best experts on this subject based on the ideXlab platform.
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tunable 975 nm nanosecond diode laser based master oscillator power amplifier system with 16 3 w peak power and narrow Spectral LineWidth below 10 pm
Optics Letters, 2014Co-Authors: T N Vu, Bernd Sumpf, Andreas Klehr, Götz Erbert, H Wenzel, Gunther TrankleAbstract:A Spectrally tunable, narrow LineWidth master oscillator power amplifier system emitting ns pulses with high peak power is presented. The master oscillator is a distributed feedback ridge waveguide (DFB-RW) laser, which is operated in continuous wave (CW) mode and emits at about 975 nm with a Spectral Line Width below 10 pm. The oscillator can be tuned over a range of 0.9 nm by varying the injection current. The tapered amplifier (TA) consists of an RW section and a flared gain-guided section. The RW section of the amplifier acts as an optical gate and converts the CW input beam emitted by the DFB-RW laser into a train of short optical pulses, which are subsequently amplified by the tapered section. The Width of the pulses is 8 ns at a repetition rate of 25 kHz. The peak power is 16.3 W. The TA preserves the Spectral properties of the emission of the DBR-RW laser. The amplified spontaneous emission is suppressed by about 40 dB.
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973 nm wavelength stabilized hybrid ns-MOPA diode laser system with 15.5 W peak power and a Spectral Line Width below 10 pm
Semiconductor Lasers and Laser Dynamics VI, 2014Co-Authors: Andreas Klehr, Hans Wenzel, Götz ErbertAbstract:A master oscillator power amplifier (MOPA) system for the generation of ns-pulses with high peak power, narrow Spectral Line Width, and stabilized emission wavelength will be presented. The master oscillator is a distributed feedback (DFB) ridge waveguide (RW) laser. The tapered amplifier consists of one RW section and one flared gain-guided section. The DFB laser is operated in continuous wave mode and emits at 973.5 nm with a Spectral Line Width below 10 pm. The RW section of the amplifier acts as an optical gate. The tapered section amplifies the generated optical pulse. An optical peak power of 15.5 W for a pulse Width of 8 ns is obtained. The emission wavelength remains constant at all output power levels of the MOPA system for a fixed current into the DFB laser. The Spectral power density of the ASE is 37 dB smaller than the lasing Spectral power density. The Spectral Line Width is smaller than 10 pm, limited by the resolution of the optical spectrum analyzer.
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wavelength stabilized ns mopa diode laser system with 16 w peak power and a Spectral Line Width below 10 pm
Semiconductor Science and Technology, 2014Co-Authors: Andreas Klehr, Hans Wenzel, Götz ErbertAbstract:A master oscillator power amplifier system for the generation of ns-pulses with high peak power, stabilized wavelength and narrow Spectral Line Width will be presented. The master oscillator is a distributed feedback (DFB) ridge waveguide (RW) laser. The tapered amplifier consists of three RW sections and one flared gain-guided section. The DFB laser is operated in continuous wave mode and emits at 1064 nm with a Spectral Line Width below 10 pm. One RW section of the amplifier acts as an optical gate for pulse selection. The tapered section amplifies the generated optical pulse. By adjusting the delay time between the current pulses injected into the picker and into the tapered section, respectively, the power of the amplified spontaneous emission was reduced below 1% of the average laser power. For an optical pulse length of 2 ns, a peak power of 16 W was obtained. A side mode suppression ratio better than 46 dB was observed.
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12 2 w output power from 1060 nm dbr tapered lasers with narrow Spectral Line Width and nearly diffraction limited beam quality
European Quantum Electronics Conference, 2009Co-Authors: K H Hasler, Götz Erbert, P Adamiec, F Bugge, H Wenzel, G Trankle, K H Hasler, F Bugge, G TrankleAbstract:High-power diode lasers with a nearly diffraction limited beam quality and a narrow Spectral Width are requested as efficient excitation sources for non-Linear frequency conversion. Semiconductor light sources offer the opportunity for an easy modulation of the light by changing the injection current. One possible application is the generation of green light by means of second harmonic generation (SHG) e.g. for flying spot laser display applications.
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1060 nm dbr tapered lasers with 12 w output power and a nearly diffraction limited beam quality
Proceedings of SPIE the International Society for Optical Engineering, 2009Co-Authors: Bernd Sumpf, J Fricke, Peter Ressel, Götz Erbert, K H Hasler, P Adamiec, F Bugge, H Wenzel, G TrankleAbstract:High-brightness narrow Line-Width 1060 nm tapered lasers with an internal distributed Bragg reflector were realized. The devices reach a maximal output power of 12 W with a narrow Spectral Line-Width below 40 pm (95% power). A nearly diffraction limited beam quality was measured up to a power of 10 W. The vertical structure is based on an InGaAs triple quantum well (TQW) active region embedded in a 4.8 μm broad AlGaAs super large optical cavity. This leads to a narrow vertical divergence of 15° (FWHM). Tapered devices were processed a total length of 6 mm consisting of 2 mm long ridge waveguide (including 1 mm DBR mirror) and 4 mm tapered sections. A full taper angle of 6° was manufactured. The input currents to both sections can be independently controlled. The devices had a conversion efficiency of about 50%. A first reliability test showed failure-free operation at 5 W without a deterioration of the beam quality and the Spectral properties.
Yolanda Gonzalez - One of the best experts on this subject based on the ideXlab platform.
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Role of re-growth interface preparation process for Spectral Line-Width reduction of single InAs site-controlled quantum dots
Nanotechnology, 2015Co-Authors: Jesús Herranz, Lukasz Jakub Wewior, Benito Alén, Luisa González, David Fuster, Yolanda GonzalezAbstract:We present growth and optical characterization measurements of single InAs site-controlled quantum dots (SCQDs) grown by molecular beam epitaxy on GaAs (001) patterned substrates by atomic force microscopy oxidation lithography. InAs SCQDs directly grown on the patterned surface were used as a seed layer and strain template for the nucleation of optically active single InAs SCQDs. The preservation of the initial geometry of the engraved pattern motifs after the re-growth interface preparation process, the lack of buffer layer growth prior to InAs seed layer deposition and the development of suitable growth conditions provide us an improvement of the SCQDs' active layer optical properties while retaining a high ratio of single occupation (89%). In this work a fivefold reduction of the average optical Line-Width from 870 μeV to 156 μeV for InAs SCQDs located 15 nm from the re-growth interface is obtained by increasing the temperature of the initial thermal treatment step of the re-growth interface from 490 °C to 530 °C.
Andreas Klehr - One of the best experts on this subject based on the ideXlab platform.
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16.3 W Peak-Power Pulsed All-Diode Laser Based Multi-Wavelength Master-Oscillator Power-Amplifier System at 964 nm
'MDPI AG', 2021Co-Authors: Tran Quoc Tien, Bernd Sumpf, Andreas Klehr, Hans Wenzel, Jörg Fricke, Gunther TrankleAbstract:An all-diode laser-based master oscillator power amplifier (MOPA) configuration for the generation of ns-pulses with high peak power, stable wavelength and small Spectral Line Width is presented. The MOPA emits alternating at two wavelengths in the Spectral range between 964 nm and 968 nm, suitable for the detection of water vapor by absorption spectroscopy. The monolithic master oscillator (MO) consists of two slightly detuned distributed feedback laser branches, whose emission is combined in a Y-coupler. The two emission wavelengths can be adjusted by varying the current or temperature to an absorption Line and to a non-absorbing region. The power amplifier (PA) consists of a ridge-waveguide (RW) section and a tapered section, monolithically integrated within one chip. The RW section of the PA acts as an optical gate and converts the continuous wave input beam emitted by the MO into a sequence of short optical pulses, which are subsequently amplified by the tapered section to boost the output power. For a pulse Width of 8 ns, a peak power of 16.3 W and a side mode suppression ratio of more than 37 dB are achieved at a repetition rate of 25 kHz. The measured Spectral Width of 10 pm, i.e., 0.1 cm−1, is limited by the resolution of the optical spectrum analyzer. The generated pulses emitting alternating at two wavelengths can be utilized in a differential absorption light detection and ranging system
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tunable 975 nm nanosecond diode laser based master oscillator power amplifier system with 16 3 w peak power and narrow Spectral LineWidth below 10 pm
Optics Letters, 2014Co-Authors: T N Vu, Bernd Sumpf, Andreas Klehr, Götz Erbert, H Wenzel, Gunther TrankleAbstract:A Spectrally tunable, narrow LineWidth master oscillator power amplifier system emitting ns pulses with high peak power is presented. The master oscillator is a distributed feedback ridge waveguide (DFB-RW) laser, which is operated in continuous wave (CW) mode and emits at about 975 nm with a Spectral Line Width below 10 pm. The oscillator can be tuned over a range of 0.9 nm by varying the injection current. The tapered amplifier (TA) consists of an RW section and a flared gain-guided section. The RW section of the amplifier acts as an optical gate and converts the CW input beam emitted by the DFB-RW laser into a train of short optical pulses, which are subsequently amplified by the tapered section. The Width of the pulses is 8 ns at a repetition rate of 25 kHz. The peak power is 16.3 W. The TA preserves the Spectral properties of the emission of the DBR-RW laser. The amplified spontaneous emission is suppressed by about 40 dB.
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973 nm wavelength stabilized hybrid ns-MOPA diode laser system with 15.5 W peak power and a Spectral Line Width below 10 pm
Semiconductor Lasers and Laser Dynamics VI, 2014Co-Authors: Andreas Klehr, Hans Wenzel, Götz ErbertAbstract:A master oscillator power amplifier (MOPA) system for the generation of ns-pulses with high peak power, narrow Spectral Line Width, and stabilized emission wavelength will be presented. The master oscillator is a distributed feedback (DFB) ridge waveguide (RW) laser. The tapered amplifier consists of one RW section and one flared gain-guided section. The DFB laser is operated in continuous wave mode and emits at 973.5 nm with a Spectral Line Width below 10 pm. The RW section of the amplifier acts as an optical gate. The tapered section amplifies the generated optical pulse. An optical peak power of 15.5 W for a pulse Width of 8 ns is obtained. The emission wavelength remains constant at all output power levels of the MOPA system for a fixed current into the DFB laser. The Spectral power density of the ASE is 37 dB smaller than the lasing Spectral power density. The Spectral Line Width is smaller than 10 pm, limited by the resolution of the optical spectrum analyzer.
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wavelength stabilized ns mopa diode laser system with 16 w peak power and a Spectral Line Width below 10 pm
Semiconductor Science and Technology, 2014Co-Authors: Andreas Klehr, Hans Wenzel, Götz ErbertAbstract:A master oscillator power amplifier system for the generation of ns-pulses with high peak power, stabilized wavelength and narrow Spectral Line Width will be presented. The master oscillator is a distributed feedback (DFB) ridge waveguide (RW) laser. The tapered amplifier consists of three RW sections and one flared gain-guided section. The DFB laser is operated in continuous wave mode and emits at 1064 nm with a Spectral Line Width below 10 pm. One RW section of the amplifier acts as an optical gate for pulse selection. The tapered section amplifies the generated optical pulse. By adjusting the delay time between the current pulses injected into the picker and into the tapered section, respectively, the power of the amplified spontaneous emission was reduced below 1% of the average laser power. For an optical pulse length of 2 ns, a peak power of 16 W was obtained. A side mode suppression ratio better than 46 dB was observed.
Gunther Trankle - One of the best experts on this subject based on the ideXlab platform.
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16.3 W Peak-Power Pulsed All-Diode Laser Based Multi-Wavelength Master-Oscillator Power-Amplifier System at 964 nm
'MDPI AG', 2021Co-Authors: Tran Quoc Tien, Bernd Sumpf, Andreas Klehr, Hans Wenzel, Jörg Fricke, Gunther TrankleAbstract:An all-diode laser-based master oscillator power amplifier (MOPA) configuration for the generation of ns-pulses with high peak power, stable wavelength and small Spectral Line Width is presented. The MOPA emits alternating at two wavelengths in the Spectral range between 964 nm and 968 nm, suitable for the detection of water vapor by absorption spectroscopy. The monolithic master oscillator (MO) consists of two slightly detuned distributed feedback laser branches, whose emission is combined in a Y-coupler. The two emission wavelengths can be adjusted by varying the current or temperature to an absorption Line and to a non-absorbing region. The power amplifier (PA) consists of a ridge-waveguide (RW) section and a tapered section, monolithically integrated within one chip. The RW section of the PA acts as an optical gate and converts the continuous wave input beam emitted by the MO into a sequence of short optical pulses, which are subsequently amplified by the tapered section to boost the output power. For a pulse Width of 8 ns, a peak power of 16.3 W and a side mode suppression ratio of more than 37 dB are achieved at a repetition rate of 25 kHz. The measured Spectral Width of 10 pm, i.e., 0.1 cm−1, is limited by the resolution of the optical spectrum analyzer. The generated pulses emitting alternating at two wavelengths can be utilized in a differential absorption light detection and ranging system
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tunable 975 nm nanosecond diode laser based master oscillator power amplifier system with 16 3 w peak power and narrow Spectral LineWidth below 10 pm
Optics Letters, 2014Co-Authors: T N Vu, Bernd Sumpf, Andreas Klehr, Götz Erbert, H Wenzel, Gunther TrankleAbstract:A Spectrally tunable, narrow LineWidth master oscillator power amplifier system emitting ns pulses with high peak power is presented. The master oscillator is a distributed feedback ridge waveguide (DFB-RW) laser, which is operated in continuous wave (CW) mode and emits at about 975 nm with a Spectral Line Width below 10 pm. The oscillator can be tuned over a range of 0.9 nm by varying the injection current. The tapered amplifier (TA) consists of an RW section and a flared gain-guided section. The RW section of the amplifier acts as an optical gate and converts the CW input beam emitted by the DFB-RW laser into a train of short optical pulses, which are subsequently amplified by the tapered section. The Width of the pulses is 8 ns at a repetition rate of 25 kHz. The peak power is 16.3 W. The TA preserves the Spectral properties of the emission of the DBR-RW laser. The amplified spontaneous emission is suppressed by about 40 dB.
Jose Luis Ballester - One of the best experts on this subject based on the ideXlab platform.
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Spectral Line Width decrease in the solar corona: resonant energy conversion from Alfv{\'e}n to acoustic waves
Astronomy & Astrophysics, 2006Co-Authors: Teimuraz V. Zaqarashvili, Ramón Oliver, Jose Luis BallesterAbstract:Observations reveal an increase with height of the Line Width of several coronal Spectral Lines probably caused by outwardly propagating Alfv{\'e}n waves. However, the Spectral Line Width sometimes shows a sudden decrease at a height 0.1-0.2 R, where the ratio of sound to Alfven speeds may approach unity. Qualitative analysis shows that the resonant energy conversion from Alfven to acoustic waves near the region of the corona where the plasma $\beta$ approaches unity may explain the observed Spectral Line Width reduction.
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Spectral Line Width decrease in the solar corona resonant energy conversion from alfven to acoustic waves
Astronomy and Astrophysics, 2006Co-Authors: Teimuraz V. Zaqarashvili, Ramón Oliver, Jose Luis BallesterAbstract:Context. Observations reveal an increase with height of the Line Width of several coronal Spectral Lines probably caused by outwardly propagating Alfven waves. However, the Spectral Line Width sometimes shows a sudden decrease at a height ∼0.1−0.2 R� ,w here the ratio of sound to Alfven speeds may approach unity. Aims. To explain the observed Line Width reduction in terms of the energy conversion from Alfven to another type of wave motion. Methods. Weakly non-Linear wave-wave interaction in ideal MHD. Results. Qualitative analysis shows that the resonant energy conversion from Alfven to acoustic waves near the region of the corona where the plasma β approaches unity may explain the observed Spectral Line Width reduction.