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Near-diffraction-limited flattop laser beam adaptively generated by stochastic parallel gradient descent algorithm
Wed, 2010-09-01 02:00 — GuestHaotong Ma, Zejin Liu, Xiaojun Xu, Sanhong Wang, Changhai Liu
We demonstrate the adaptive generation of a near-diffraction-limited flattop laser beam in the near field based on the stochastic parallel gradient descent algorithm and dual-phase-only liquid crystal spatial light modulators (LC-SLMs). One LC-SLM redistributes the intensity, and the other ... [Opt. Lett. 35, 2973-2975 (2010)]
In situ measurement and reconstruction in three dimensions of femtosecond inscription-induced complex permittivity modification in glass
Wed, 2010-09-01 02:00 — GuestA. V. Turchin, Mykhaylo Dubov, J. A. R. Williams
We demonstrate a new approach to in situ measurement of femtosecond-laser-pulse-induced changes in glass, enabling the three-dimensional reconstruction of the induced complex permittivity modification. The technique can be used to provide single-shot and time-resolved quantitative measurements with ... [Opt. Lett. 35, 2952-2954 (2010)]
Suppression of stimulated Raman scattering employing long period gratings in double-clad fiber amplifiers
Wed, 2010-09-01 02:00 — GuestD. Nodop, C. Jauregui, F. Jansen, J. Limpert, A. Tünnermann
We report on the suppression of stimulated Raman scattering (SRS) in a double-clad fiber amplifier using long-period gratings (LPGs). The LPGs, fabricated with a CO_2 laser, achieve SRS suppression by coupling the Stokes wavelength from the active core into the cladding. With only three LPGs ... [Opt. Lett. 35, 2982-2984 (2010)]
Use of tapered amplifier diode laser for biological-friendly high-resolution optical trapping
Wed, 2010-09-01 02:00 — GuestWei Cheng, Ximiao Hou, Fangmao Ye
A 1064nm laser is commonly used for biological optical trapping. However, it has the problem of generating reactive oxygen species in the presence of a sensitizer, which leads to photo damage in biological samples. Here we constructed optical tweezers using a tapered amplifier diode laser that ... [Opt. Lett. 35, 2988-2990 (2010)]
Pulse energy of 151 nJ from ultrafast thulium-doped chirped-pulse fiber amplifier
Wed, 2010-09-01 02:00 — GuestFrithjof Haxsen, Dieter Wandt, Uwe Morgner, Joerg Neumann, Dietmar Kracht
We report on chirped-pulse amplification of an ultrafast thulium-doped fiber laser. Pulses with an energy of 3.3nJ and a bandwidth-limited pulse duration of 195fs could be amplified to 151nJ, which corresponds to an average power of 5.7W at 37.6MHz pulse repetition rate. The maximum output power ... [Opt. Lett. 35, 2991-2993 (2010)]
Passive mode locking in a Ti:sapphire laser using a single-walled carbon nanotube saturable absorber at a wavelength of 810 nm
Sun, 2010-08-15 02:00 — GuestDmitry V. Khudyakov, Anatoly S. Lobach, Viktor A. Nadtochenko
We report mode locking in a Ti:sapphire (Ti:Sa) laser at the wavelength of 810nm using a polymer film with single-walled carbon nanotubes (SWNTs) applied as a saturable absorber. Pulses with 600fs duration and 0.4nJ energy were generated from the Ti:Sa laser with polymer-SWNT composite film for cw ... [Opt. Lett. 35, 2675-2677 (2010)]
Continuous-wave spontaneous lasing in mercury pumped by resonant two-photon absorption
Sun, 2010-08-15 02:00 — GuestDaniel Kolbe, Martin Scheid, Andreas Koglbauer, Jochen Walz
We demonstrate the first cw two-photon absorption laser-induced stimulated emission. The 7^1S_0−6^1P_1 transition in mercury at a 1014nm wavelength is used, and selective lasing of different isotopes is observed. [Opt. Lett. 35, 2690-2692 (2010)]
Fracture-induced subbandgap absorption as a precursor to optical damage on fused silica surfaces
Sun, 2010-08-15 02:00 — GuestP. E. Miller, J. D. Bude, T. I. Suratwala, N. Shen, T. A. Laurence, W. A. Steele, J. Menapace, M. D. Feit, L. L. Wong
The optical damage threshold of indentation-induced flaws on fused silica surfaces was explored. Mechanical flaws were characterized by laser damage testing, as well as by optical, secondary electron, and photoluminescence microscopy. Localized polishing, chemical leaching, and the control of ... [Opt. Lett. 35, 2702-2704 (2010)]
Broadband emission spectrum dynamics of large water droplets exposed to intense ultrashort laser radiation
Sun, 2010-08-15 02:00 — GuestYuri E. Geints, Andrey M. Kabanov, Gennadii G. Matvienko, Victor K. Oshlakov, Alexander A. Zemlyanov, Sergey S. Golik, Oleg A. Bukin
We report on experiments on the interaction of a gigawatt femtosecond laser pulse train with hanging isolated millimeter-sized water droplets. A transparent droplet experienced explosive boiling-up and emitted light in the visible spectrum as a result of laser-induced plasma formed inside the ... [Opt. Lett. 35, 2717-2719 (2010)]
High-repetition-rate, high-peak-power, linear-polarized 473 nm Nd:YAG/BiBO blue laser by extracavity frequency doubling
Sun, 2010-08-15 02:00 — GuestFei Chen, Xin Yu, Renpeng Yan, Xudong Li, Cheng Wang, Junhua Yu, Zhonghua Zhang
We report on a high-repetition-rate, high-peak-power, linear-polarized 473nm blue laser. A high-power 946nm fundamental laser was obtained based on a diode-pumped acousto-optically (AO) Q-switched Nd:YAG laser using a thermal-compensating resonator and a microchannel heat sink for thermal ... [Opt. Lett. 35, 2714-2716 (2010)]
