The Experts below are selected from a list of 13746 Experts worldwide ranked by ideXlab platform
Andrew M. Weiner - One of the best experts on this subject based on the ideXlab platform.
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line by line Pulse Shaping with spectral resolution below 890 mhz
Optics Express, 2012Co-Authors: John T Willits, Andrew M. Weiner, Steven T CundiffAbstract:Line-by-line Pulse Shaping is demonstrated on a 890 MHz repetition rate mode-locked titanium sapphire laser. The high resolution Pulse shaper is based on a virtual imaged phased array (VIPA) with a free spectral range of 25 GHz. For our implementation, the mask repeats every VIPA free spectral range, which corresponds to every 28 comb lines. Individual frequency modes from the laser are also resolved using the same VIPA paired with a diffraction grating to achieve a resolution of 357 MHz. Several output waveforms are compared with simulation to understand differences with the ideal case.
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spectral line by line Pulse Shaping of on chip microresonator frequency combs
Nature Photonics, 2011Co-Authors: Fahmida Ferdous, Daniel E Leaird, Houxun Miao, Kartik Srinivasan, Jian Wang, Lei Chen, Leo T Varghese, Andrew M. WeinerAbstract:Researcher demonstrate the line-by-line Pulse Shaping of frequency combs generated in silicon nitride ring resonators, and observe two distinct paths to comb formation that exhibit strikingly different time domain behaviours.
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ultrafast optical Pulse Shaping a tutorial review
Optics Communications, 2011Co-Authors: Andrew M. WeinerAbstract:article i nfo Article history: This paper presents a tutorial on the field of femtosecond Pulse Shaping, a technology that enables generation of nearly arbitrary, user defined, ultrafast optical waveforms, with control of phase, amplitude, and polari- zation. The emphasis is on Fourier transform Pulse Shaping, the most widely applied technique. Selected Pulse Shaping applications are described, with specific discussion of coherent control of quantum and nonlinear processes and of lightwave communications. Two new areas of Pulse Shaping research, namely, hyperfine spectral resolution Pulse Shaping and Pulse Shaping applications in ultrabroadband RF photonics, are discussed and illustrated with examples taken from the author's laboratory.
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microwave photonic filter based on optical comb and line by line optical Pulse Shaping
Conference on Lasers and Electro-Optics, 2010Co-Authors: Ehsan Hamidi, Daniel E Leaird, Andrew M. WeinerAbstract:We demonstrate microwave photonic filters based on optical combs with large number of taps and more than 30-dB sidelobe suppression. We program and tune the filter's bandpass by utilizing line-by-line Pulse Shaping and optical delay.
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femtosecond Pulse Shaping in two dimensions towards higher complexity optical waveforms
Optics Express, 2008Co-Authors: V R Supradeepa, Chen-bin Huang, Daniel E Leaird, Andrew M. WeinerAbstract:We demonstrate a new Fourier Pulse Shaping apparatus capable of achieving simultaneous high resolution and broad bandwidth operation by dispersing frequency components in a two dimensional geometry through simultaneous use of a high resolution and a broad bandwidth spectral disperser. We show experimental results which demonstrate significant improvements in achievable waveform complexity (number of controllable temporal/spectral features). We also demonstrate experiments of line-by-line Pulse Shaping with optical frequency combs. In this regime our configuration would allow significant enhancement of the number of controllable spectral lines which may further enhance recently demonstrated massively parallel approaches to spectroscopic sensing using frequency combs.
Daniel E Leaird - One of the best experts on this subject based on the ideXlab platform.
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spectral line by line Pulse Shaping of on chip microresonator frequency combs
Nature Photonics, 2011Co-Authors: Fahmida Ferdous, Daniel E Leaird, Houxun Miao, Kartik Srinivasan, Jian Wang, Lei Chen, Leo T Varghese, Andrew M. WeinerAbstract:Researcher demonstrate the line-by-line Pulse Shaping of frequency combs generated in silicon nitride ring resonators, and observe two distinct paths to comb formation that exhibit strikingly different time domain behaviours.
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microwave photonic filter based on optical comb and line by line optical Pulse Shaping
Conference on Lasers and Electro-Optics, 2010Co-Authors: Ehsan Hamidi, Daniel E Leaird, Andrew M. WeinerAbstract:We demonstrate microwave photonic filters based on optical combs with large number of taps and more than 30-dB sidelobe suppression. We program and tune the filter's bandpass by utilizing line-by-line Pulse Shaping and optical delay.
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femtosecond Pulse Shaping in two dimensions towards higher complexity optical waveforms
Optics Express, 2008Co-Authors: V R Supradeepa, Chen-bin Huang, Daniel E Leaird, Andrew M. WeinerAbstract:We demonstrate a new Fourier Pulse Shaping apparatus capable of achieving simultaneous high resolution and broad bandwidth operation by dispersing frequency components in a two dimensional geometry through simultaneous use of a high resolution and a broad bandwidth spectral disperser. We show experimental results which demonstrate significant improvements in achievable waveform complexity (number of controllable temporal/spectral features). We also demonstrate experiments of line-by-line Pulse Shaping with optical frequency combs. In this regime our configuration would allow significant enhancement of the number of controllable spectral lines which may further enhance recently demonstrated massively parallel approaches to spectroscopic sensing using frequency combs.
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spectral line by line Pulse Shaping on an optical frequency comb generator
IEEE Journal of Quantum Electronics, 2007Co-Authors: Z Jiang, Chen-bin Huang, Daniel E Leaird, Houxun Miao, M Kourogi, Kazuhiro Imai, Andrew M. WeinerAbstract:We demonstrate optical processing based on spectral line-by-line Pulse Shaping of a frequency comb generated by an optical frequency comb generator (OFCG). The OFCG is able to generate a smooth, broad, stable, known-phase frequency comb, which is ideal for recently developed spectral line-by-line Pulse Shaping technology applications. We demonstrate line-by-line Pulse Shaping on 64 lines at 10-GHz line spacing, generate transform-limited 1.6-ps short Pulses at 10 GHz by combining two Pulses in each period directly from the OFCG, and show various examples for optical arbitrary waveform generation. Further, we demonstrate that these Pulse sources are of sufficient quality to support optical fiber communication applications as confirmed by bit error rate measurements.
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optical processing based on spectral line by line Pulse Shaping on a phase modulated cw laser
IEEE Journal of Quantum Electronics, 2006Co-Authors: Z Jiang, Daniel E Leaird, Andrew M. WeinerAbstract:We demonstrate optical processing based on spectral line-by-line Pulse Shaping of a frequency comb generated by phase modulating a CW laser and show various applications including CW-to-Pulse conversion, width/wavelength tunable return-to-zero Pulse generation, Pulse-to-CW conversion, wavelength conversion, and microwave photonics. The correlations between optical spectra, time-domain waveforms, and RF spectra are quantitatively studied
Z Jiang - One of the best experts on this subject based on the ideXlab platform.
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spectral line by line Pulse Shaping on an optical frequency comb generator
IEEE Journal of Quantum Electronics, 2007Co-Authors: Z Jiang, Chen-bin Huang, Daniel E Leaird, Houxun Miao, M Kourogi, Kazuhiro Imai, Andrew M. WeinerAbstract:We demonstrate optical processing based on spectral line-by-line Pulse Shaping of a frequency comb generated by an optical frequency comb generator (OFCG). The OFCG is able to generate a smooth, broad, stable, known-phase frequency comb, which is ideal for recently developed spectral line-by-line Pulse Shaping technology applications. We demonstrate line-by-line Pulse Shaping on 64 lines at 10-GHz line spacing, generate transform-limited 1.6-ps short Pulses at 10 GHz by combining two Pulses in each period directly from the OFCG, and show various examples for optical arbitrary waveform generation. Further, we demonstrate that these Pulse sources are of sufficient quality to support optical fiber communication applications as confirmed by bit error rate measurements.
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optical processing based on spectral line by line Pulse Shaping on a phase modulated cw laser
IEEE Journal of Quantum Electronics, 2006Co-Authors: Z Jiang, Daniel E Leaird, Andrew M. WeinerAbstract:We demonstrate optical processing based on spectral line-by-line Pulse Shaping of a frequency comb generated by phase modulating a CW laser and show various applications including CW-to-Pulse conversion, width/wavelength tunable return-to-zero Pulse generation, Pulse-to-CW conversion, wavelength conversion, and microwave photonics. The correlations between optical spectra, time-domain waveforms, and RF spectra are quantitatively studied
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line by line Pulse Shaping control for optical arbitrary waveform generation
Quantum Electronics and Laser Science Conference, 2006Co-Authors: Z Jiang, Daniel E Leaird, Andrew M. WeinerAbstract:We demonstrate line-by-line Pulse Shaping control for optical arbitrary waveform generation (O-AWG). Independent manipulation of individual spectral lines from a mode-locked frequency comb leads to synthesis of user-specified ultrafast optical waveforms with unprecedented frequency resolution.
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line by line Pulse Shaping control for optical arbitrary waveform generation
Optics Express, 2005Co-Authors: Z Jiang, Daniel E Leaird, Andrew M. WeinerAbstract:We demonstrate a fundamental operation for generating complex waveforms in the optical domain – line-by-line Pulse Shaping control for optical arbitrary waveform generation (O-AWG). Independent manipulation of the spectral amplitude and phase of individual lines from a mode-locked frequency comb, or spectral line-by-line Pulse Shaping, leads to synthesis of user-specified ultrafast optical waveforms with unprecedented control. Coupled with recent advances in frequency stabilized mode-locked lasers, line-by-line Pulse Shaping control should have significant impact to fields drawing upon developments in the field of ultrafast science.
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spectral line by line Pulse Shaping
Conference on Lasers and Electro-Optics, 2005Co-Authors: Andrew M. Weiner, Chen-bin Huang, Z Jiang, Daniel E Leaird, Jose CaraquitenaAbstract:In this paper, we review spectral line-by-line Pulse Shaping, including examples of waveform generation, data demonstrating sensitivity to comb offset frequency, and requirements for high fidelity waveform generation. In order to achieve spectral line-by-line Pulse Shaping, we have improved the spectral resolution of grating-based Pulse shapers to ~2.5 GHz, and performed experiments utilizing high repetition rate (~10 GHz) Pulse sources, including harmonically mode-locked fiber lasers and strongly phase modulated CW lasers.
P Petropoulos - One of the best experts on this subject based on the ideXlab platform.
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Pulse Shaping in mode locked fiber lasers by in cavity spectral filter
Optics Letters, 2014Co-Authors: Sonia Boscolo, Christophe Finot, Huseyin Karakuzu, P PetropoulosAbstract:We numerically show the possibility of Pulse Shaping in a passively mode-locked fiber laser by inclusion of a spectral filter into the laser cavity. Depending on the amplitude transfer function of the filter, we are able to achieve various regimes of advanced temporal waveform generation, including ones featuring bright and dark parabolic-, flat-top-, triangular- and saw-tooth-profiled Pulses. The results demonstrate the strong potential of an in-cavity spectral Pulse shaper for controlling the dynamics of mode-locked fiber lasers.
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broadband flat frequency comb generated using Pulse Shaping assisted nonlinear spectral broadening
IEEE Photonics Technology Letters, 2013Co-Authors: Xin Yang, D J Richardson, P PetropoulosAbstract:In this letter, we demonstrate the nonlinear generation of a low noise, ultra-flat frequency comb covering the full C-band. The comb is generated using nonlinear spectral broadening on a mode-locked laser, assisted by adaptive Pulse Shaping. A linear Pulse Shaping element, which is dynamically controlled by an adaptive algorithm exploiting the covariance matrix adaptation evolution strategy, is placed prior to a nonlinear element. A 3-dB bandwidth of 35 nm is achieved, and the power variations about a central region of 30 nm are less than 1 dB.
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Pulse Shaping assisted nonlinear spectral broadening
European Quantum Electronics Conference, 2011Co-Authors: Xin Yang, D J Richardson, P PetropoulosAbstract:Recent developments in optical fibre technology have allowed significant advances in the nonlinear generation and tailoring of broadband spectra. Much work in this direction has focused on the optimisation of the properties of the optical fibres used for the nonlinear Pulse propagation. In this work, we combine the nonlinear element (a highly nonlinear fibre - HNLF) with a programmable phase and amplitude filter, which we use as a Pulse shaper. This architecture allows power-efficient and flexible sculpturing of the output spectrum, which is no longer tied directly to the characteristics of the Pulse source used at the input. The Pulse Shaping function is obtained by application of the inverse split-step Fourier method (ISSFM) [1], which uses the desired output spectrum and the HNLF characteristics as its input parameters [2]. As an example of the application of this technique, we study the generation of broadband flat (third-order super-Gaussian) spectra starting from a 10GHz mode-locked Pulsed laser (MLL). Here we present our design procedure and a first experimental validation of the technique.
Neil Hopkinson - One of the best experts on this subject based on the ideXlab platform.
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selective laser melting of inconel 625 using Pulse Shaping
Rapid Prototyping Journal, 2010Co-Authors: Kamran Mumtaz, Neil HopkinsonAbstract:Purpose – The purpose of this paper is to investigate the selective laser melting (SLM) of Inconel 625 using Pulse shape control to vary the energy distribution within a single laser Pulse. It aims to discuss the effectiveness of Pulse Shaping, including potential benefits for use within SLM.Design/methodology/approach – Laser parameters were varied in order to identify optimal parameters that produced thin wall parts with a low surface roughness without the use of Pulse shape control. Pulse shape control was then employed to provide gradual heating or a prolonged cooling effect with a variety of peak power/Pulse energy combinations. Properties of Pulse shaped and nonPulse shaped parts were compared, with particular attention focused on part surface roughness and width.Findings – High peak powers tended to reduce top surface roughness and reduce side roughness as recoil pressures flatten out the melt pool and inhibit melt pool instabilities from developing. Ramp up energy distribution can reduce the maxim...
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selective laser melting of thin wall parts using Pulse Shaping
Journal of Materials Processing Technology, 2010Co-Authors: Kamran Mumtaz, Neil HopkinsonAbstract:Pulse Shaping is a technique used to temporally distribute energy within a single laser Pulse. This provides the user an added degree of control over the heat delivered to the laser material interaction zone. Pulses that induce a gradual heating or a prolonged cooling effect can be generated with peak power/Pulse energy combinations specifically tailored to control melt pool properties and eventual part formation. This investigation used a Pulsed 550 W Nd:YAG laser to produce thin wall Inconel 625® parts using Pulse shapes that delivered a variety of different energy distributions. Parts built with and without Pulse shape control were measured for width, top and side surface roughness. The efficacy of Pulse Shaping control is discussed including potential benefits for use within the Selective Laser Melting process. Pulse Shaping was shown to reduce spatter ejection during processing, improve the top surface roughness of parts and minimise melt pool width.
