Virtual Journal of Laser

G. K. Samanta, S. Chaitanya Kumar, M. Ebrahim-Zadeh
We present a stable, high-power, cw, single-frequency green source in a compact and practical design based on a simple single-pass second-harmonic generation of a cw ytterbium fiber laser at 1064 nm in MgO-doped periodically poled stoichiometric LiTaO_3. Using a 30-mm-long crystal containing a ... [Opt. Lett. 34, 1552-1554 (2009)]

Shumpei Kameyama, Masaharu Imaki, Yoshihito Hirano, Shinichi Ueno, Shuji Kawakami, Daisuke Sakaizawa, Masakatsu Nakajima
We have demonstrated the 1.6 μm cw modulation hard-target differential absorption lidar system for CO_2 sensing. In this system, ON and OFF wavelength laser lights are intensity modulated with cw signals. Received lights of the two wavelengths from the hard target are discriminated by ... [Opt. Lett. 34, 1513-1515 (2009)]

M. Dubinskii, J. Zhang, V. Ter-Mikirtychev
We report the performance of a resonantly cladding-pumped, Yb-free, Er-doped fiber laser. We believe this is the first reported resonantly cladding-pumped fiber-Bragg-grating-based, Er-doped, large-mode-area (LMA) fiber laser. The laser, pumped by fiber-coupled InGaAsP/InP laser diode modules at ... [Opt. Lett. 34, 1507-1509 (2009)]

Ge Zhang, Haiyong Zhu, Chenghui Huang, Jing Chen, Yong Wei, Lingxiong Huang
In this Letter, a high-power diode-side-pumped Nd:YAG laser emitting at 1338 nm is described. The output characteristics of the laser using the different output couplers for both the cw mode and the Q-switched mode have been studied. With a pumping power of 555 W, the average output power decreases ... [Opt. Lett. 34, 1495-1497 (2009)]

Da-Wun Chen, Milton Birnbaum, Paul M. Belden, Todd S. Rose, Steven M. Beck
The cw and Q-switched performance of Er:YAG lasers operating at 1645 nm were measured. Guided by previous work in the literature, we sought to improve efficiency at low pulse repetition frequencies by decreasing the doping level from 0.5 to 0.25 at.% to reduce upconversion losses. Only a small ... [Opt. Lett. 34, 1501-1503 (2009)]

Zhongchi Luo, Zhijia Yuan, Yingtian Pan, Congwu Du
A dual-wavelength laser speckle contrast imaging technique (DW-LSCI) is presented for simultaneous imaging of cerebral blood flow and hemoglobin oxygenation changes at high spatiotemporal resolutions. Experimental validation was performed using a rat transient forebrain ischemia model. The results ... [Opt. Lett. 34, 1480-1482 (2009)]

Johan Boullet, Yoann Zaouter, Jens Limpert, Stéphane Petit, Yann Mairesse, Baptiste Fabre, Julien Higuet, Eric Mével, Eric Constant, Eric Cormier
We report the first experimental demonstration (to our knowledge) of high-order harmonic generation in rare gases driven by a state-of-the-art high-power Yb-doped-fiber chirped-pulse amplification system. The fiber laser delivers 270 fs pulses in the 30-100 μJ energy range at repetition rates ... [Opt. Lett. 34, 1489-1491 (2009)]

Selcuk Akturk, Cord L. Arnold, Bing Zhou, Andre Mysyrowicz
We demonstrate compression of high-energy ultrashort laser pulses by nonlinear propagation inside gas-filled planar hollow waveguides. We adjust the input beam size along the nonguided dimension of the planar waveguide to restrain the intensity below photoionization, while the relatively long range ... [Opt. Lett. 34, 1462-1464 (2009)]

F. Friebel, F. Druon, J. Boudeile, D. N. Papadopoulos, M. Hanna, P. Georges, P. Camy, J. L. Doualan, A. Benayad, R. Moncorgé, C. Cassagne, G. Boudebs
We demonstrate the generation of 99 fs pulses by a mode-locked laser oscillator built around a Yb:CaF_2 crystal. An average power of 380 mW for a 13 nm bandwidth spectrum centered at 1053 nm is obtained. The short-pulse operation is achieved thanks to a saturable absorber mirror and is stabilized ... [Opt. Lett. 34, 1474-1476 (2009)]

N. Brimhall, N. Heilmann, M. Ware, J. Peatross
We demonstrate a technique for determining optical constants of materials in the extreme UV from the ratio of p-polarized to s-polarized reflectance. The measurements are based on laser-generated high-order harmonics, which have easily rotatable linear polarization but that are prone to brightness ... [Opt. Lett. 34, 1429-1431 (2009)]