T. Y. Fan

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—Beam combining of laser arrays with high efficiency and good beam quality for power and radiance (brightness) scaling is a long-standing problem in laser technology. Recently, significant progress has been made using wavelength (spectral) techniques and coherent (phased array) techniques, which has led to the demonstration of beam combining of a large(More)
Fiber lasers are well suited to scaling to high average power using beam-combining techniques. For coherent combining, optical phase-noise characterization of a ytterbium fiber amplifier is required to perform a critical evaluation of various approaches to coherent combining. For wavelength beam combining, we demonstrate good beam quality from the(More)
N-nitrosodiethanolamine has been found to be present at a concentration of 0.02 to 3 percent in several brands of synthetic cutting fluids. Its identity was confirmed by three independent techniques: (i) by measuring the retention times on two different high-performance liquid-chromatography columns, (ii) by dehydration to N-nitrosomorpholine, and (iii) by(More)
Wavelength beam combining was used to co-propagate beams from 28 elements in an array of distributed-feedback quantum cascade lasers (DFB-QCLs). The beam-quality product of the array, defined as the product of near-field spot size and far-field divergence for the entire array, was improved by a factor of 21 by using wavelength beam combining. To demonstrate(More)
Using empirical analyses of the effects of global climate change (GCC) and ocean acidification (OA) on the survival and calcification of early life stages of Pocillopora damicornis, we employed a demographic approach to forecast the consequences of GCC and OA on the population dynamics of this coral. We constructed a size-based demographic model using(More)
Nonlinear optics plays a key role in many applications not only as a means of frequency synthesis and control, but also as a source of twin photons and other nonclas-sical states of light. Advances in nonlinear materials, including engineered nonlinear interactions through the use of quasi-phase matching, have increased the flexibility and performance of(More)
  • Hong Citation, Kyung-Han, Chien-Jen Lai, Aleem Siddiqui, Franz X Kartner, Kyung-Han Hong +82 others
  • 2009
"130-W picosecond green laser based on a frequency-doubled hybrid cryogenic Yb:YAG amplifier," Opt. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits(More)
III The use of diode lasers instead ofHashlamps as optical pump sources for solid state lasers offers significant advantages such as higher efficiency and longer lifetime. We have demonstrated three novel lasers based on this technology. The first is a zigzag slab laser pumped by hybrid planar microchannel-cooled diode arrays that allow high-repetition-rate(More)
Airborne N-nitrosomorpholine (0 to 27 micrograms per cubic meter) was found in two of four rubber industry factories. N-Nitrosodimethylamine was also found in two factories, but at lower levels. These findings may be relevant to the reported increased risk of certain types of cancer in rubber workers in some of the same areas where the N-nitrosomorpholine(More)
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