Showing papers on "Regenerative amplification published in 2004"
TL;DR: The boundaries between stable and unstable pulsing are identified and stability criteria in dependence on the amplifier gate length and pump power are discussed.
Abstract: Multi-energy and chaotic pulse energy output from a continuously pumped regenerative amplifier is observed for dumping rates around the inverse upper state lifetime of the gain medium The relevant regimes of operation are analyzed numerically and experimentally in a diode-pumped Yb:glass regenerative amplifier The boundaries between stable and unstable pulsing are identified and stability criteria in dependence on the amplifier gate length and pump power are discussed
98 citations
TL;DR: Phase-stabilized 12-fs, 1-nJ pulses from a commercial Ti:sapphire oscillator are directly amplified in a chirped-pulse optical parametric amplifier and recompressed to yield near-transform-limited 17.3-fs pulses.
Abstract: Phase-stabilized 12-fs, 1-nJ pulses from a commercial Ti:sapphire oscillator are directly amplified in a chirped-pulse optical parametric amplifier and recompressed to yield near-transform-limited 17.3-fs pulses. The amplification process is demonstrated to be phase preserving and leads to 85‐µJ, carrier-envelope-offset phase-locked pulses at 1 kHz for 0.9 mJ of pump, corresponding to a single-pass gain of 8.5×104.
71 citations
TL;DR: A carrier-envelope phase (CEP) stabilized chirped-pulse amplification (CPA) system employing a grating-based pulse stretcher and compressor and a regenerative amplifier is demonstrated for the first time.
Abstract: We have demonstrated a carrier-envelope phase (CEP) stabilized chirped-pulse amplification (CPA) system employing a grating-based pulse stretcher and compressor and a regenerative amplifier for the first time. In addition to stabilizing the carrier-envelope offset phase of a laser oscillator, a new pulse selection method referenced to the carrier-envelope offset beat signal was introduced. The pulse-selection method is more robust against the carrier-envelope offset phase fluctuations than a simple pulse-clock dividing method. We observed a stable fringe in a self-referencing spectrum interferometry of the amplified pulse, which implies that the CEP of amplified pulse is stabilized. We also measured the effect of the beam angle change on the CEP of amplified pulses. The result demonstrates that the CEP stabilized CPA is scalable to higher-pulse energies.
69 citations
TL;DR: The optical gain-depletion-induced mode-locking dynamics of a semiconductor optical-amplifier-based fiber ring laser (SOAFL) backward injected by a purely sinusoidally modulated or digitally encoded distributedfeedback laser diode are theoretically and experimentally demonstrated.
Abstract: The optical gain-depletion-induced mode-locking dynamics of a semiconductor optical-amplifier-based fiber ring laser (SOAFL) backward injected by a purely sinusoidally modulated or digitally encoded distributedfeedback laser diode are theoretically and experimentally demonstrated. The effect of gain depletion and waveform on the mode-locked pulse width, pulse shape, and power of the SOAFL are interpreted from theoretical simulations. The shortest pulse width of 12 ps can be generated from an optically sinusoidal-wave-modulated SOAFL. By backward injecting the SOAFL with a digitally encoded optical signal of adjustable duty cycle, one can observe the optimized gain depletion time of 400-600 ps required for mode locking the SOAFL.
54 citations
TL;DR: The results demonstrate experimentally that there is not a strong coupling mechanism between CEP and beam pointing through a stretcher/compressor, as well as measuring significantly smaller CEP fluctuations than experimental results reported previously.
Abstract: In this work, we experimentally investigate the effect of a grating based pulse stretcher/compressor on the carrier-envelope phase stability of femtosecond pulses. Grating based stretcher-compressor (SC) setups have been avoided in past demonstrations of chirped pulse amplification (CPA) of carrier envelope phase (CEP) stabilized femtosecond pulses, because they were expected to introduce significantly stronger CEP fluctuations than material-based SC systems. Using a microstructure fiber-based detection setup, we measure CEP fluctuations of ΔΦCE,SC=340 milliradians rms for a frequency range from 63 mHz to 102 kHz for pulses propagating through the SC setup. When bypassing the beam path through the SC, we find CEP fluctuations of ΔΦCE,bypass=250 milliradians rms. These values contain significant contributions from amplitude-to-phase conversion in our microstructure fiber-based detection setup for ΔΦCE. Hence, we do not unambiguously measure any added CEP noise intrinsic to the SC setup. To distinguish between intrinsic SC effects and amplitude-to-phase conversion, we introduce controlled beam pointing fluctuations Δα and again compare the phase noise introduced when passing through/bypassing the SC. Our measurements do not reveal any intrinsic effects of the SC system, but allow us to place an upper limit on the sensitivity of our SC system of ΔΦCEintrinsic,SC/Δα<13000 rad/rad. Our results demonstrate experimentally that there is not a strong coupling mechanism between CEP and beam pointing through a stretcher/compressor, as well as measuring significantly smaller CEP fluctuations than experimental results reported previously.
37 citations
TL;DR: The high gain and large bandwidth obtained for single-stage nondegenerate OPCPA operation provide a compact and efficient solution for amplification of ultrashort pulses near 1.57 microm.
Abstract: We demonstrate optical parametric chirped pulse amplification (OPCPA) at 1-kHz repetition rate in periodically poled stoichiometric LiTaO3 (PPSLT) with 1 mol % MgO doping. Diode pumping was used both for the fiber laser generating the femtosecond seed pulses and the nanosecond laser/amplifier employed as a pump source. The high gain (≈63 dB) and large bandwidth (20 nm) obtained for single-stage non-degenerate OPCPA operation provide a compact and efficient solution for amplification of ultrashort pulses near 1.57 µm. Stretched femtosecond pulses could be amplified up to 39.5 µJ in a 7-mm long, 2-mm thick sample of PPSLT. The pulse duration of the amplified signal pulses (FWHM) after recompression amounted to 315 fs.
36 citations
TL;DR: An Yb:KYW thin-disk amplifier system that provides ultrashort pulses in the 10-microJ energy range at high repetition rates is reported, without using a traditional diffraction-grating stretcher.
Abstract: We report an Yb:KYW thin-disk amplifier system that provides ultrashort pulses in the 10‐µJ energy range at high repetition rates. The thin-disk concept uses large laser beam cross sections to avoid high peak intensities. Without using a traditional diffraction-grating stretcher, pulse energies of approximately 9 µJ with pulse durations of 280 fs at repetition rates of 200 kHz were generated.
33 citations
TL;DR: A diode-pumped Nd:YLF regenerative amplifier (regen) has been developed and is in use in the 60-beam, 30-kJ UV Omega laser system's driver line and shows excellent long-term output-pulse-energy stability.
Abstract: A diode-pumped Nd:YLF regenerative amplifier (regen) has been developed and is in use in the 60-beam, 30-kJ UV Omega laser system's driver line. The high stability, the compactness, and the reliability of this all-solid-state modular design are the key features of this concept. Stable, millijoule-level output-pulse energies with an overall gain of 10(9) have been demonstrated. Excellent long-term output-pulse-energy stability of better than 1% rms fluctuations has been achieved with excellent beam quality (<1% ellipticity).
31 citations
TL;DR: Noncoherent x-ray radiation is generated and applied in an all-solid-state laser system operating at repetition rates up to 20 kHz based on a model that takes into account the strong thermal loading of the Ti:sapphire rod.
Abstract: We have generated and applied noncoherent x-ray radiation in an all-solid-state laser system operating at repetition rates up to 20 kHz. Based on a model that takes into account the strong thermal loading of the Ti:sapphire rod, a laser cavity with low sensitivity to thermal lensing was chosen. With a maximum pump power of 80 W, an output power as high as 27 W was obtained in gain-switched operation, and, with a seeding from a femtosecond oscillator, 60-fs, 0.8-mJ (8-W) pulses at 10 kHz and 0.32-mJ (6.5-W) pulses at 20 kHz were generated. High power femtosecond output was used to generate x-ray continuum radiation up to 5 keV from a liquid-gallium jet target.
21 citations
01 Feb 2004
TL;DR: In this paper, the designs to generate nanosecond pulses with thin disk lasers as well as the results of the results were discussed, and the output of the regenerative amplifier was tunable within 10 nm around 1030 nm.
Abstract: The designs to generate nanosecond pulses with thin disk lasers as well as the results will be discussed. In Q-switched operation 18 mJ pulse energy at 1 kHz repetition rate with a pulse duration of 230 ns have been achieved. Cavity dumping is also demonstrated with 12 mJ pulse energy at 1 kHz and a pulse duration of 30 ns. In an amplifier set-up 37 mJ at 1 kHz with 9 ns pulse length (FWHM) have been demonstrated. The additional advantage of this set-up is the possibility to adjust both spectral and temporal shape of the output pulses and the output energy, independently. The output of the regenerative amplifier was tunable within 10 nm around 1030 nm.
16 citations
01 Feb 2004
TL;DR: In this article, an improved Yb:KYW thin disk amplifier system was proposed to provide ultra short pulses with high energies at high repetition rates without using CPA, 100-µJ, 750-fs pulses were generated with up to 45 kHz.
Abstract: We report of an improved Yb:KYW thin disk amplifier system to provide ultra short pulses with high energies at high repetition rates. Without using CPA, 100-µJ, 750-fs pulses were generated with up to 45 kHz.
TL;DR: It is demonstrated that the combination of two BBO crystals makes it possible to spectrally shape the amplified pulses, and the possibility to achieve broader spectral range amplification is confirmed for a non-collinear pump-signal interaction geometry.
Abstract: A chirped pulse, spectrally broadened in a photonic bandgap optical fiber by 120 fs Ti:Sapphire laser pulses, is parametrically amplified in a BBO crystal pumped by a frequency doubled nanosecond Nd:YAG laser pulse. Without changing the frequency of the Ti:Sapphire, a spectral tunability of the amplified pulses is demonstrated. The possibility to achieve broader spectral range amplification is confirmed for a non-collinear pump-signal interaction geometry. For optimal non-collinear interaction geometry, the pulse duration of the original and amplified pulse are similar. Finally, we demonstrate that the combination of two BBO crystals makes it possible to spectrally shape the amplified pulses.
TL;DR: In this article, an active prelasing stabilization loop has been implemented acting on the mode locker, allowing stable operation up to repetition rates as high as 3 kHz, and sub-30-ps pulses with an energy of 800 μJ have been achieved.
Abstract: Picosecond pulse generation by active mode locking and subsequent regenerative amplification in a Nd:vanadate laser crystal has been realized in one and the same cavity using the all-in-one laser concept. An active prelasing stabilization loop has been implemented acting on the mode locker, allowing stable operation up to repetition rates as high as 3 kHz. Sub-30-ps pulses with an energy of 800 μJ have been achieved, constituting the highest peak power and the highest average output power ever demonstrated by means of the all-in-one approach. The combination of compact design, high peak and average power along with a near-diffraction-limited beam profile makes this source a promising tool for precision micromachining applications.
01 Jan 2004
TL;DR: In this paper, high repetition rate femtosecond sources tunable from 250 nm to 2 μm have been demonstrated, based on Ti:sapphire and using FemTosecond Optical Parametric Amplification to achieve broad tunability.
Abstract: We demonstrate high repetition rate femtosecond sources tunable from 250 nm to 2 μm. These sources are based on Ti:sapphire and use Femtosecond Optical Parametric Amplification to achieve broad tunability.
Proceedings Article•
16 May 2004TL;DR: In this paper, an Yb:KYW thin disk amplifier system was proposed to provide ultra short pulses with high energies at high repetition rates, at a repetition rate of up to 45 kHz.
Abstract: We report of an Yb:KYW thin disk amplifier system to provide ultra short pulses with high energies at high repetition rates. Without using chirped pulse amplification, 100 /spl mu/J, 750 fs pulses were generated at repetition rates of up to 45 kHz.
TL;DR: In this paper, the authors compare the frequency detuning properties of the optical pulses generated from erbium-doped fiber laser (EDFL) by using harmonic mode-locking and regenerative amplification techniques.
Abstract: We compare the frequency detuning properties of the optical pulses generated from erbium-doped fiber lasers (EDFL’s) by using harmonic mode-locking and regenerative amplification techniques The frequency detuning range of regeneratively amplified pulse (1778 kHz) is wider than that of harmonic mode-locked pulses (7 kHz) The regeneratively amplidied EDFL pulse has a smaller pulsewidth (22 ps), a higher peak power (407 mW), a lower phase noise (-107 dBc/Hz at offset frequency of 100 kHz), and a lower timing jitter (033 ps) This is attributed to that the characteristic of the gain-switched optical pulse is remained under regenerative amplification operation Our harmonic mode-locked erbium-doped fiber laser has a lower phase noise (-100 dBc/Hz @ offset 1 kHz; -105 dBc/Hz @ 10 kHz) than that ever reported in a regeneratively harmonic mode-locked fiber ring laser
TL;DR: Photonic millimeter-wave generation from high-order frequencymultiplied optical pulse-train of Erbium-doped fiber laser (EDFL) harmonic mode-locked at repetition frequency of 1 GHz is demonstrated.
Abstract: Photonic millimeter-wave generation from high-order frequencymultiplied optical pulse-train of Erbium-doped fiber laser (EDFL) harmonic mode-locked at repetition frequency of 1 GHz is demonstrated. A Fabry-Perot laser diode (FPLD) operated at below threshold condition is employed as an intra-cavity optical mode-locker, which is purely sinusoidal-wavemodulated at 1 GHz without any DC biased current in this experiment. The threshold modulating power of 18 dBm for the FPLD is observed for harmonic mode-locking the EDFL. The frequency-multiplication of EDFL pulse-train is implemented by detuning the modulating frequency of the FPLD. At highest repetition rate of 42 GHz, the peak power and pulseswidth of frequency-multiplied EDFL pulse-train are 140 mW and 2.7 ps, respectively.
Proceedings Article•
16 May 2004TL;DR: In this paper, a review of new ytterbium doped crystals (Yb:GdCOB, Yb:BOYS and yb:SYS) used to develop sub-100-fs diode-pumped oscillators at around 1 /spl mu/m and a regenerative amplifier producing 380-fs, up to 100-/spl µ/j at 350-Hz.
Abstract: We present a review of new ytterbium doped crystals (Yb:GdCOB, Yb:BOYS and Yb:SYS) used to develop sub-100-fs diode-pumped oscillators at around 1 /spl mu/m and a regenerative amplifier producing 380-fs, up to 100-/spl mu/j at 350-Hz.
TL;DR: Chirped pulse optical parametric amplification of CEO phase-stabilized, 1.7nJ, 11.6fs pulses from a Ti:sapphire oscillator yielded 77-?J, 17.3-fs pulses with the CEO phase lock preserved as mentioned in this paper.
Abstract: Chirped pulse optical parametric amplification of CEO phase-stabilized, 1.7-nJ, 11.6-fs pulses from a Ti:sapphire oscillator yielded 77-?J, 17.3-fs pulses with the CEO phase lock preserved. A full numerical 3D study predicted single-pass amplification to 97 ?J and compression to 12.7 fs.
Proceedings Article•
16 May 2004TL;DR: In this article, a laser system developed as the front end for a multipetawatt-class laser that uses an optical parametric chirped-pulse amplifier as a preamplifier and a glass power amplifier is described.
Abstract: We report on a laser system developed as the front end for a multipetawatt-class laser that uses an optical parametric chirped-pulse amplifier as a preamplifier and a glass power amplifier. Early results are presented.
TL;DR: In this article, a 40 GHz regeneratively amplified and frequency-multiplied optical pulse train from an erbium-doped fiber ring laser is demonstrated, which is achieved by seeding a 1 GHz gain-switched Fabry-Perot laser diode and detuning its repetition frequency to coincide with the harmonic resonant cavity mode.
Abstract: The generation of a 40 GHz regeneratively amplified and frequency-multiplied optical pulse train from an erbium-doped fiber ring laser is demonstrated. This is achieved by seeding a 1 GHz gain-switched Fabry–Perot laser diode and detuning its repetition frequency to coincide with the harmonic resonant cavity mode. The peak power of frequency-multiplied erbium-doped fiber lasers (EDFL) pulses increases from 80 mW to 230 mW as the modulation level of the Fabry–Perot laser diode (FPLD) increases from 18 dBm to 30 dBm. The pulsewidth and peak power are 10 ps and 5 mW at a repetition rate of 40 GHz. The EDFL longitudinal mode frequency fluctuation is within ±2.5 kHz during 2 h. The frequency-multiplied EDFL pulses exhibit relatively low phase noises of -95 dBc/Hz and -120 dBc/Hz at offset frequencies of 10 kHz and 1 MHz, respectively. The associated timing jitter of the EDFL pulses exponentially increases from 0.6 ps to beyond 5.8 ps as the frequency multiplication order increases from 1 to 40.
01 Jan 2004
TL;DR: In this article, the authors developed new crystal growth methods which produce high-concentration Ti:sapphire crystals (α488 > 4 cm-1) with high single-pass gain over 40dB by double-side.
Abstract: We have developed new crystal- growth methods which produce high-concentration Ti:sapphire crystals (α488 > 4 cm-1) with high single-pass-gain over 40-dB by double-side.
Proceedings Article•
18 Jul 2004TL;DR: In this article, the authors demonstrate how the zone of cyclotron suppression of generation in a resonant TWT can be exploited to amplify an external signal by adjusting the value of the guide magnetic field from its resonant value.
Abstract: We demonstrate how the zone of cyclotron suppression of generation in a resonant TWT can be exploited to amplify an external signal. The appearance of a stop-band, when a resonant interaction of a fast cyclotron wave of the electron beam with a counter-propagating electromagnetic wave takes place, determines the absorption of the reflected electromagnetic wave from the output end of the interaction space. As one adjusts the value of the guide magnetic field from its resonant value to the boundaries of the zone of cyclotron absorption, which represent the threshold of self-excitation, we observe an increase in the amplitude of the reflected wave, which is responsible for positive feedback, on the input end of the interaction space. The result is in increased regenerative amplification.
01 Jan 2004
TL;DR: In the past two years, Cr:LiSAF has become an attractive alternative gain medium for the high intensity amplification of femtosecond optical pulses as discussed by the authors, and it has a relatively long upperstate lifetime of 67 μs permitting efficient flashlamp-pumping, leading to compact laboratory sized low-cost amplifiers using a mature technology developed in many years for Nd:glass based amplifier systems.
Abstract: In the past two years Cr:LiSAF has become an attractive alternative gain medium for the high intensity amplification of femtosecond optical pulses.1-6 Cr:LiSAF uniquely combines the advantages of Ti:sapphire and Nd:glass, materials commonly used as gain media in laser systems based on chirped pulse amplification7. Cr:LiSAF has a broad spectral emission bandwidth similar to that of Ti:sapphire allowing the amplification of femtosecond optical pulses. In addition Cr:LiSAF has a relatively long upperstate lifetime of 67 μs permitting efficient flashlamp-pumping8 leading to compact laboratory sized low-cost amplifiers using a mature technology developed in many years for Nd:glass based amplifier systems.
Proceedings Article•
16 May 2004TL;DR: In this paper, q-preserving multi-pass cavities (MPCs) are used in the construction of high-energy and compact ultrashort pulse sources, and the application of MPC designs to femtosecond Ti/sup 3+/:Al/sub 2/O/sub 3/ lasers is described.
Abstract: We present a general analysis of q-preserving multi-pass cavities (MPC) which can be used in the construction of high-energy and compact ultrashort pulse sources. The application of MPC designs to femtosecond Ti/sup 3+/:Al/sub 2/O/sub 3/ lasers is described.
01 Jan 2004
TL;DR: Chirped-pulse amplification was used to generate 0.35 mJ, 55 fs pulses in Ti:Al2O3 in this article, and the modeling done to produce this result and the limitations of the methods used were discussed.
Abstract: Chirped-pulse amplification is used to generate 0.35 mJ, 55 fs pulses in Ti:Al2O3. We discuss the modeling done to produce this result and the limitations of the methods used. The use of a kHz post-amplifier is also discussed.
02 Aug 2004
TL;DR: In this article, the design and performance of an OPCPA system operating at 1550 nm is presented, with the pump laser and the broadband phase matching in RTP and KTA.
Abstract: We present the design and performance of an OPCPA system operating at 1550 nm. The pump laser and the broadband phase matching in RTP and KTA are discussed in detail.
TL;DR: In this article, the carrier-envelope offset (CEO) phase is preserved in a chirped-pulse optical parametric amplifier (CPOPA), which yields 85-µJ CEO phase-stabilized pulses that are recompressed to a near-transform-limited duration of 17.3 fs.
Abstract: We demonstrate the preservation of the carrier-envelope offset (CEO) phase in a chirped-pulse optical parametric amplifier (CPOPA), which yields 85-µJ CEO phase-stabilized pulses that are recompressed to a near-transform-limited duration of 17.3 fs.
01 Feb 2004
TL;DR: In this article, a high gain optical parametric chirped-pulse amplifier for Nd:glass-based short pulse laser systems based on periodically poled potassium-titanyl-phosphate was demonstrated.
Abstract: We have demonstrated a high-gain optical parametric chirped-pulse amplifier for Nd:glass-based short-pulse laser systems based on periodically poled potassium-titanyl-phosphate. Our amplifier produced high single-pass gain, broad bandwidth, excellent beam quality and stability.
TL;DR: In this paper, two Pockels cells were used in series to achieve simple temporal pulse shaping, which has been used in our optical parametric chirp pulse amplification (OPCPA) system to optimize the temporal shape of the pump pulse, providing a low cost alternative to arbitrary waveform generators.
Abstract: We have used two Pockels cells in series to achieve simple temporal pulse shaping. This technique has been used in our optical parametric chirp pulse amplification (OPCPA) system to optimize the temporal shape of the pump pulse, providing a low cost alternative to arbitrary waveform generators.