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Binh T. Do

Bio: Binh T. Do is an academic researcher from Sandia National Laboratories. The author has contributed to research in topics: Laser & Pulse duration. The author has an hindex of 8, co-authored 17 publications receiving 336 citations.

Papers
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Journal ArticleDOI
TL;DR: The bulk and surface dielectric breakdown thresholds of pure silica for 14 ps and 8 ns pulses of 1064 nm light are measured and are sharp and reproducible.
Abstract: We measured bulk and surface dielectric breakdown thresholds of pure silica for 14 ps and 8 ns pulses of 1064 nm light. The thresholds are sharp and reproducible. For the 8 ns pulses the bulk threshold irradiance is 4.75 +/- 0.25 kW/microm2. The threshold is approximately three times higher for 14 ps pulses. For 8 ns pulses the input surface damage threshold can be made equal to the bulk threshold by applying an alumina or silica surface polish.

186 citations

Proceedings ArticleDOI
14 Apr 2008
TL;DR: The Sandia National Laboratories' program in high-power fiber lasers has emphasized development of enabling technologies for power scaling and gaining a quantitative understanding of fundamental limits, particularly for high-peak-power, pulsed fiber sources.
Abstract: Sandia National Laboratories' program in high-power fiber lasers has emphasized development of enabling technologies for power scaling and gaining a quantitative understanding of fundamental limits, particularly for high-peak-power, pulsed fiber sources This paper provides an overview of the program, which includes: (1) power scaling of diffraction-limited fiber amplifiers by bend-loss-induced mode filtering to produce >1 MW peak power and >1 mJ pulse energy with a practical system architecture; (2) demonstration of a widely tunable repetition rate (71-27 kHz) while maintaining constant pulse duration and pulse energy, linear output polarization, diffraction-limited beam quality, and <1% pulse-energy fluctuations; (3) development of microlaser seed sources optimized for efficient energy extraction; (4) high-fidelity, three-dimensional, time-dependent modeling of fiber amplifiers, including nonlinear processes; (5) quantitative assessment of the limiting effects of four-wave mixing and self-focusing on fiber-amplifier performance; (6) nonlinear frequency conversion to efficiently generate mid-infrared through deep-ultraviolet radiation; (7) direct diode-bar pumping of a fiber laser using embedded-mirror side pumping, which provides 20x higher efficiency and much more compact packaging than traditional approaches employing formatted, fiber-coupled diode bars; and (8) fundamental studies of materials properties, including optical damage, photodarkening, and gamma-radiation-induced darkening

31 citations

Journal ArticleDOI
TL;DR: The bulk optical damage thresholds of pure and Nd-doped ceramic yttrium aluminum garnet (YAG) are measured to determine that the breakdown thresholds are deterministic, with multiple-pulse thresholds ranging from 1.1 to 2.2 kJ/cm2.
Abstract: We measured the bulk optical damage thresholds of pure and Nd-doped ceramic yttrium aluminum garnet (YAG), and of pure, Nd-doped, Cr-doped, and Yb-doped crystalline YAG. We used 9.9 ns, 1064 nm, single-longitudinal mode, TEM00 pulses, to determine that the breakdown thresholds are deterministic, with multiple-pulse thresholds ranging from 1.1 to 2.2 kJ/cm2.

25 citations

Proceedings ArticleDOI
TL;DR: In this paper, the performance of mode-filtered, Yb-doped fiber amplifiers seeded by microchip lasers with nanosecond-duration pulses is discussed. But the authors focus on the specific regime of nanoseccond pulses and do not consider the effects of pulse duration, wavelength, and linewidth.
Abstract: We summarize the performance of mode-filtered, Yb-doped fiber amplifiers seeded by microchip lasers with nanosecond-duration pulses. These systems offer the advantages of compactness, efficiency, high peak power, diffraction-limited beam quality, and widely variable pulse energy and repetition rate. We review the fundamental limits on pulsed fiber amplifiers imposed by nonlinear processes, with a focus on the specific regime of nanosecond pulses. Different design options for the fiber and the seed laser are discussed, including the effects of pulse duration, wavelength, and linewidth. We show an example of a microchip-seeded, single-stage, single-pass fiber amplifier that produced pulses with 1.1 MW peak power, 0.76 mJ pulse energy, smooth temporal and spectral profiles, diffractionlimited beam quality, and linear polarization.

21 citations

Proceedings ArticleDOI
TL;DR: In this article, the authors used a TEM 00 laser at 1.064 µm, with 7.5nsec pulse duration, focused to a 7.45mm-radius spot in bulk fused silica.
Abstract: The objective of this work is to understand catastrophic optical damage in nanosecond pulsed fiber amplifiers. We used a pulsed, single longitudinal mode, TEM 00 laser at 1.064 µm, with 7.5-nsec pulse duration, focused to a 7.45-mm-radius spot in bulk fused silica. Our bulk damage threshold irradiance is corrected to account for self focusing. The pulse to pulse variation in the damage irradiance in pure silica is less than 1%. Damage is nearly instantaneous, with an induction time much less than 1 ns. These observations are consistent with an electron avalanche rate equation model, using reasonable rate coefficients. The bulk optical breakdown threshold irradiance of pure fused silica is 5.0x1011 ±7% Watts/cm 2 . We also measured the surface damage threshold irradiance of 1% Yb 3+ doped fused silica preform of Liekki Yb1200 fiber, and found it is equal to that of pure silica within 2%. The optical damage morphology is reproducible from pulse to pulse. To facilitate the morphology study we developed a technique for locating the laser focus based on the third harmonic signal generated at the air-fused silica interface. This gives a very small uncertainty in focal position (~ 10 mm) which is important in interpreting the damage structure. The surface third harmonic method was also used to determine the laser focus spot size and verify beam quality. Earlier reports have claimed that the damage irradiance depends strongly on the size of the focal spot. We varied the focal volume to look for evidence of this effect, but found none.

20 citations


Cited by
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Journal ArticleDOI
TL;DR: This paper reviews the current state of the art in terms of continuous-wave and pulsed performance of ytterbium-doped fiber lasers, the current fiber gain medium of choice, and by far the most developed in Terms of high-power performance.
Abstract: The rise in output power from rare-earth-doped fiber sources over the past decade, via the use of cladding-pumped fiber architectures, has been dramatic, leading to a range of fiber-based devices with outstanding performance in terms of output power, beam quality, overall efficiency, and flexibility with regard to operating wavelength and radiation format. This success in the high-power arena is largely due to the fiber’s geometry, which provides considerable resilience to the effects of heat generation in the core, and facilitates efficient conversion from relatively low-brightness diode pump radiation to high-brightness laser output. In this paper we review the current state of the art in terms of continuous-wave and pulsed performance of ytterbium-doped fiber lasers, the current fiber gain medium of choice, and by far the most developed in terms of high-power performance. We then review the current status and challenges of extending the technology to other rare-earth dopants and associated wavelengths of operation. Throughout we identify the key factors currently limiting fiber laser performance in different operating regimes—in particular thermal management, optical nonlinearity, and damage. Finally, we speculate as to the likely developments in pump laser technology, fiber design and fabrication, architectural approaches, and functionality that lie ahead in the coming decade and the implications they have on fiber laser performance and industrial/scientific adoption.

1,689 citations

Journal ArticleDOI
TL;DR: In this article, the fundamental properties and latest developments in high-power fiber lasers are summarized and reviewed, focusing primarily on the most common fiber laser configurations and the associated cladding pumping issues.
Abstract: In this paper, we summarize the fundamental properties and review the latest developments in high power fiber lasers. The review is focused primarily on the most common fiber laser configurations and the associated cladding pumping issues. Special attention is placed on pump combination techniques and the parameters that affect the brightness enhancement observed in single-mode and multimode high power fiber lasers. The review includes the major limitations imposed by fiber nonlinearities and other parasitic effects, such as optical damage, transverse modal instabilities and photodarkening. Finally, the paper summarizes the power evolution in continuous-wave and pulsed ytterbium-doped fiber lasers and their impact on industrial applications.

812 citations

Journal ArticleDOI
TL;DR: In this article, the authors provide an overview of recent progress in ns-, ps-, and fs-CARS spectroscopy for gas-phase thermometry and species-concentration measurements since the second edition of A.C. Eckbreth's book entitled Laser Diagnostics for Combustion Temperature and Species.

404 citations

Journal ArticleDOI
TL;DR: In this paper, a review of fiber laser technology as relevant for applications in ultrafast optics is given, focusing on systems built around passively mode-locked fiber lasers and fiber frequency combs, which are further amplified in large-core fiber amplifiers.
Abstract: In this paper, a review of fiber laser technology as relevant for applications in ultrafast optics is given. We discuss core enabling fiber technologies, such as fiber amplifiers, all-fiber dispersion control, and highly nonlinear and large-core fibers. We concentrate on systems built around passively mode-locked fiber lasers and fiber frequency combs, which are further amplified in large-core fiber amplifiers. Our review further encompasses coherent supercontinuum generation and techniques for absolute phase control of fiber lasers and amplifiers. Applications concerned with spectral generation in the range from the vacuum UV to the terahertz range are also described.

340 citations

Journal ArticleDOI
TL;DR: In this paper, a review of diode laser-based spectroscopy is presented, which covers the developments made so far and illustrates the properties of free-running diode lasers.
Abstract: Spectroscopy using tunable diode lasers is an area of research that has gone through a dramatic evolution over the last few years, principally because of new exciting approaches in the field of atomic and molecular spectroscopy. This article attempts to review major recent advancements in the field of diode laser based spectroscopy. The discussion covers the developments made so far in the field of diode lasers and illustrates comprehensively the properties of free-running diode lasers. Since the commercially available free-running diode lasers are not suitable for high-precision spectroscopic studies, various techniques developed so far for converting these free-running diode lasers into true narrow linewidth tunable laser sources are discussed comprehensively herein. The potential uses of diode lasers in different spectroscopic fields and their extensive list of applications have also been included, which may be interesting for the novice and the advanced user as well.

304 citations