Showing papers on "Femtosecond pulse shaping published in 1989"
TL;DR: A simple model is presented to describe mode locking in a laser coupled to a nonlinear resonator, which reveals a new mechanism for pulse shortening and shows that shortening does not rely on dispersion in the auxiliary cavity.
Abstract: A simple model is presented to describe mode locking in a laser coupled to a nonlinear resonator. It reveals a new mechanism for pulse shortening and shows that shortening does not rely on dispersion in the auxiliary cavity. Experimental results are given to support the basic predictions of the model.
223 citations
TL;DR: Evidence that soliton pulse shaping is playing a key role in the formation of the pulses is presented, showing that mode-locked erbium-doped fiber laser pulses are generated from a wide-bandwidth, lithium niobate guided-wave modulator.
Abstract: We have generated pulses as short as 4 psec at 1530 nm from a mode-locked erbium-doped fiber laser. The mode locker is a wide-bandwidth, lithium niobate guided-wave modulator, and the fiber laser is completely integrated. We present evidence that soliton pulse shaping is playing a key role in the formation of the pulses.
146 citations
70 citations
TL;DR: It is shown that an interplay between the effects of group-velocity dispersion and cross-phase modulation can lead to optical wave breaking that manifests as rapid oscillations near the leading or the trailing side of the probe pulse.
Abstract: When a probe pulse copropagates with a pump pulse inside an optical fiber, the two can interact through cross-phase modulation. It is shown that an interplay between the effects of group-velocity dispersion and cross-phase modulation can lead to optical wave breaking that manifests as rapid oscillations near the leading or the trailing side of the probe pulse. Qualitative features of this new kind of optical wave breaking are discussed, as well as the conditions under which it can be observed experimentally. The probe pulse can be compressed significantly by optimizing the initial delay between the pump and probe pulses even when the two pulses experience normal dispersion in the fiber.
61 citations
01 Jan 1989
TL;DR: In this article, the basic principles of light pulse compression through chirp generation and compensation inside and outside the laser cavity are discussed, including various linear and nonlinear optical processes that have gained importance in compression techniques.
Abstract: Ultrashort light pulses obtained by pulse compression are widely used in the various fields of science, medicine and engineering, including spectroscopy, optoelectronics, communication techniques and material processing. This book focuses on the basic principles of light pulse compression through chirp generation and compensation inside and outside the laser cavity. Beginning with a brief introduction to ultrashort light pulses, the latest experimental and theoretical achievements are reviewed, including the various linear and nonlinear optical processes that have gained importance in compression techniques and contributed to pulse shaping in prisms, gratings, optical fibers and saturable media. The important femtosecond pulse lasers based on intracavity pulse compression and the use of chirped pulses in ultrafast measuring techniques are also discussed. Researchers, teaching scientists and professionals involved in physics, electrical, optical and laser engineering will find this volume a useful source of reference.
43 citations
TL;DR: In this paper, four different schemes for the generation of femtosecond input pulses for ArF amplifiers are described, including phase-matched frequency mixing of a Raman-shifted frequency-doubled pulse derived from a 537-nm femto-cond dye-laser pulse.
Abstract: Four different schemes for the generation of femtosecond input pulses for ArF amplifiers are described. Pulse energies of 100 nJ were obtained with phase-matched frequency mixing of a Raman-shifted frequency-doubled pulse derived from a 537-nm femtosecond dye-laser pulse. Excellent spatial, spectral, and amplitude stability was obtained when a broadband, nanosecond dye laser at 690 nm was used as a Raman seed pulse. Preliminary amplification experiments resulted in 0.5-mJ ArF output pulses of 340 fsec.
30 citations
TL;DR: In this paper, a general procedure for determining pulse asymmetry including time direction is described, where the pulse form is reconstructed iteratively for each pulse, yet time direction remains ambiguous.
Abstract: A general procedure for determining pulse asymmetry including time direction is described. Fundamental and second‐harmonic interferometric autocorrelations are measured before and after passing through a glass block. Pulse form is reconstructed iteratively for each pulse, yet time direction is ambiguous. Time direction for both pulses is then simultaneously determined by phase curvature comparison in the frequency domain, taking the known dispersion of the glass block into account. This results in complete evaluation of ultrashort optical pulses. This method is demonstrated successfully for passively mode‐locked dye laser pulses.
29 citations
TL;DR: In this article, a high-power KrF laser system is presented providing 45 mJ, 150 fs pulses at the position of a target, which is avoided by specially designed refractive optics.
Abstract: A high-power KrF laser system is presented providing 45 mJ, 150 fs pulses at the position of a target. Pulse front distortion is avoided by specially designed refractive optics. Pulse compression is done after final amplification using a simplified compressor.
28 citations
TL;DR: In this article, a tunable sub-picosecond infrared pulse was generated in the 1.4-1.6 μm region by mixing a 1.064 μm Nd:YAG laser pulse and a visible sub-posecond pulse from a cavity dumped, synchronously pumped dye laser.
Abstract: Tunable subpicosecond infrared pulses have been generated in the 1.4–1.6 μm region by mixing a 1.064 μm Nd:YAG laser pulse and a visible subpicosecond pulse from a cavity dumped, synchronously pumped dye laser. Pulses as short as 94 fs with a peak power of 8.4 kW have been obtained with a KTP crystal at a rate of 3.8 MHz.
27 citations
TL;DR: In this article, a two-temperature model predicts that the optical damage threshold of metals will be independent of the optical pulse duration for short pulses, and experiments performed with picosecond 10 um pulses confirm this prediction.
Abstract: An ultrashort light pulse illuminating a metal surface interacts primarily with the electrons. During a transient phase the electrons can be much hotter than the lattice. A two-temperature model predicts that the optical damage threshold of metals will be independent of the optical pulse duration for short pulses. Experiments performed with picosecond 10 um pulses confirm this prediction. The model also predicts, and we experimentally observe, electron emission during the transient phase even for illumination intensities below the damage threshold.
23 citations
TL;DR: In this paper, a 180-fs UV pulse has been generated based on a hybrid synchronously pumped mode-locked dye laser for a multiterawatt KrF laser system and the pulse width was measured by the single shot autocorrelation technique with the three-photon fluorescence of the XeF C-A transition.
Abstract: A 180-fs UV pulse has been generated based on a hybrid synchronously pumped mode-locked dye laser for a multiterawatt KrF laser system. The pulse width was measured by the single shot autocorrelation technique with the three-photon fluorescence of the XeF C-A transition. The pulse width broadening due to dispersive media was investigated. The results show that the observed pulse width broadening from 210 fs to 390 fs through the entire system is explained mostly by the linear dispersion of the optical elements for near-transform-limited input pulses.
TL;DR: In this article, the temporal profiles of picosecond light pulses by filtration through photochemically-burned spectral holes are demonstrated experimentally, and the output pulse profiles calculated via the Fourier and Hilbert transformations from transparency spectra coincide with the ones measured directly.
TL;DR: In this article, a traveling-wave semiconductor laser amplifier was used to amplify optical pulses with durations ranging from 0.49 to 21 ps. The saturation characteristics were successfully explained by a four-level system model.
Abstract: Optical pulses with durations ranging from 0.49 to 21 ps are amplified by a traveling-wave semiconductor laser amplifier. The pulse energy gain is determined by pulse energy only. The dependence of pulse energy gain on output pulse energy does not change in the pulse duration range. The saturation characteristics are successfully explained by a four-level system model. >
TL;DR: In this paper, the authors studied the temporal profile of the picosecond laser pulse scattered from random media in the backward direction in two angular regions: Coherent (-1.5 mrad) and diffuse (7.9 mrad).
Abstract: We have studied the temporal profile of the picosecond laser pulse scattered from random media in the backward direction in two angular regions: Coherent (-1\ensuremath{\le}\ensuremath{\theta}\ensuremath{\le}1 mrad) and diffuse (7.5\ensuremath{\le}\ensuremath{\theta}\ensuremath{\le}9.5 mrad), using a streak camera with overall 15-ps time resolution. To give a good description of the temporal profile of the scattered pulse, in addition to a diffusion term, terms from the maximally crossed diagrams are required to account for the coherent enhancement of scattered intensity in the backward direction due to time-reversal symmetry.
TL;DR: In this paper, the authors proposed a spectral filter to simplify the intracavity shaping mechanisms in such a way that the nonlinear Schrodinger equation becomes a good approximation for pulse generation in the laser.
Abstract: The generation of solitons and other related periodic pulse evolutions in a passively mode-locked dye laser is controlled by adjustment of group velocity dispersion, self-phase modulation, and spectral filtering. Without spectral filtering, periodic pulse evolutions reminiscent of higher-order solitons are observed. The pulses differ from the classic solitons because of additional shaping mechanisms. With spectral filtering, pulses are generated that can be described analytically as true asymmetric N=2 solitons. The introduction of the filter appears to simplify the intracavity shaping mechanisms in such a way that the nonlinear Schrodinger equation becomes a good approximation for pulse generation in the laser. The remarkable stability achieved allows for accurate characterization and control. >
TL;DR: In this paper, the power spectrum of the optical pulse train for mutually incoherent fluctuations of the turn-on delay time and the pulse amplitude is calculated, and it is shown that a measurement of the spectrum alone is not sufficient for the characterization of the inherent timing jitter.
Abstract: Methods to assess pulse to pulse timing jitter in periodicallly gain‐switched semiconductor lasers are investigated. The power spectrum of the optical pulse train for mutually incoherent fluctuations of the turn‐on delay time and the pulse amplitude is calculated. The result shows that a measurement of the power spectrum alone is not sufficient for the characterization of the inherent timing jitter. Additional knowledge of the optical waveform and the transfer characteristics of the detection system is necessary.
TL;DR: A 440-fsec, 0.1-pJ pulse from a dye laser is injected into a high-repetition-rate Ti:Al(2)O(3) laser pumped by a copper-vapor laser to study the amplification and pulse broadening of femtosecond pulses in Ti:al(2), with gains of 2 x 10(7) omitting dispersion broadening.
Abstract: A 440-fsec, 0.1-pJ pulse from a dye laser is injected into a high-repetition-rate Ti:Al(2)O(3) laser pumped by a copper-vapor laser to study the amplification and pulse broadening of femtosecond pulses in Ti:Al(2)O(3). Gains of 2 x 10(7) are achieved with output pulse durations of 1.1 psec. After recompression with a grating pair to compensate dispersion broadening, pulses as short as 275 fsec are obtained.
TL;DR: In this paper, a simple system consisting of an amplified spontaneous emission source (ASE), a grating and a traveling wave (TW) amplifier which were pumped by the amplified output of a colliding-pulse mode-locked dye laser permits generation of continuously tunable femtosecond pulses.
TL;DR: In this article, the influence of depletable amplification, group velocity dispersion and self-phase modulation due to Kerr-type nonlinearity on pulse shaping in femtosecond pulse amplification has been calculated.
Abstract: The influence of depletable amplification, group velocity dispersion and self-phase modulation due to Kerr-type nonlinearity on pulse shaping in femtosecond pulse amplification has been calculated. With gain depletion which is typical for the last stage of multi-stage amplifiers, spectral broadening occurs which, under certain conditions, can be utilized for pulse compression. This spectral broadening as well as a predicted spectral shift is compared with experimental results.
TL;DR: In this paper, the influence of an intensity variation across the beam cross-section and of changing the beam diameter along the path through a nonlinear medium is considered, and the application of bulk media for the pulse shaping as well as the limits to this kind of compression are discussed.
Abstract: The compression of high-energy femtosecond light pulses is investigated theoretically. The influence of an intensity variation across the beam cross-section and of changing the beam diameter along the path through a nonlinear medium are considered. The application of bulk media for the pulse shaping as well as the limits to this kind of compression are discussed.
TL;DR: In this paper, the femtosecond and tunable picosecond laser pulses have been generated using a linear cavity configuration in both lasers, and the long-term stability of the synchronization, as well as the frequency of the synchronously pumped femto-cond dye laser, is assured by active stabilization of the cavity length.
Abstract: Synchronized femtosecond and tunable picosecond laser pulses have been generated using a linear cavity configuration in both lasers. The long-term stability of the synchronization, as well as the frequency of the synchronously pumped femtosecond dye laser, is assured by active stabilization of the cavity length. Additionally, the picosecond and femtosecond pulses have been amplified in dual amplifier chains to pulse energies in the microjoule range at a 1 kHz repetition rate. The total peak intensity available for two-photon, nonlinear excitations is on the order of 10/sup 9/ times greater than that available from unamplified beams. >
TL;DR: A synchronously pumped, hybridly mode-locked, antiresonant-ring dye laser that is insensitive to cavity-length variations of up to 15 microm is described, and no evidence for colliding-pulse mode-locking effects is observed.
Abstract: A synchronously pumped, hybridly mode-locked, antiresonant-ring dye laser that is insensitive to cavity-length variations of up to 15 μm is described. At a cavity length that is 70–80 μm shorter than the synchronous cavity length this laser generates stable pulses as short as 55 fsec, with a pulse width of 65 fsec being typical (assuming a sech2 pulse shape). No evidence for colliding-pulse mode-locking effects is observed.
TL;DR: In this paper, a rapid scanning interferometric SHG autocorrelator was developed for real-time monitoring of frequency sweep in femtosecond optical pulses, which can be used successfully for measuring inter-ferometric auto-correlation traces of femto-cond pulses generated from a colliding pulse mode-locked dye laser and those from a hybrid-mode-locked, cavity-dumped dye laser.
TL;DR: In this paper, it was shown that a periodic pulse train is completely restored after propagating a distance in a dispersive medium that depends on the period and the dispersion, which is a fundamental property of the parabolic differential equation that governs pulse propagation.
Abstract: It is shown that a periodic pulse train is completely restored after propagating a distance in a dispersive medium that depends on the period and the dispersion. This is a fundamental property of the parabolic differential equation that governs pulse propagation in dispersive media. This phenomenon could be applicable in photonic systems. >
26 May 1989
TL;DR: In this article, the authors focus on the nonlinear auxiliary fiber resonator as a termination with an effective reflectivity, and describe how this reflectivity changes as a function of the auxiliary cavity length.
Abstract: The authors focus on the nonlinear auxiliary fiber resonator as a termination with an effective reflectivity. They describe how this reflectivity changes as a function of the auxiliary cavity length, compare theoretical predictions with experimental results, and discuss the optimum cavity length adjustment for short pulse generation. >
01 Jan 1989
TL;DR: In this paper, a transmission-line laser model was used to isolate the mechanisms responsible for temporal pulse compression and broadening and investigate the conditions required for this form of pulse distortion.
Abstract: Semiconductor laser amplifiers can exhibit either temporal pulse compression or broadening. A transmission-line laser model was used to isolate the mechanisms responsible and to investigate the conditions required for this form of pulse distortion. Results show that gain saturation is the dominant temporal compression mechanism in travelling wave laser amplifiers, and that filtering may account for some compression in Fabry-Perot laser amplifiers. Compression is highly dependent on the input pulse shape, being zero for Gaussian-like pulses. This means that it is unlikely to be useful for shortening pulses produced by highly modulated injection lasers. However, compression can occur with pulses with a slowly decaying trailing edge, but only over a limited range of input powers. Pulse broadening is also caused by gain saturation and is again dependent on the input pulse shape, being zero for square-edged pulses. For Gaussian pulses, the broadening is negligible for input pulse energies below the amplifier's saturation energy. This suggests that TWLAs may be used to boost the power of pulses from mode-locked semiconductor lasers. These results are in excellent agreement with other worker's experimental results. >
Proceedings Article•
24 Apr 1989
TL;DR: A new figure of merit is defined for the mode-locker design, which indicates that sapphire is a good substrate material for acousto-optic mode locker design.
Abstract: We modeled, designed, and built a 500-MHz acousto-optic mode locker with a diffraction efficiency of 28% per 1 W drive power. The transducer is zinc oxide sputtered onto a sapphire substrate. A new figure of merit is defined for the mode-locker design, which indicates that sapphire is a good substrate material. Pulse widths of less than 10 psec with an average power of 150 mW were achieved from a 500-MHz pulse-rate, diode-pumped, cw mode-locked Nd:YLF laser using a pump power of 700 mW.
TL;DR: The first demonstration and experimental details of a technique for measuring the pulse temporal profile of a single picosecond pulse at a wavelength of 249 nm are reported.
Abstract: We report the first demonstration and give experimental details of a technique for measuring the pulse temporal profile of a single picosecond pulse at a wavelength of 249 nm.