Virtual Journal of Laser

Alex Terray, H. D. Ladouceur, Mark Hammond, Sean J. Hart
Optical chromatography achieves microscale optical manipulation through the balance of optical and hydrodynamic forces on micron sized particles entrained in microfluidic flow traveling counter to the propagation of a mildly focused laser beam. The optical pressure force on a particle is specific ... [Virtual J. Biomed. Opt. 17, 2024-2032 (2009)]

Milan P. Poudel
We have studied the possible nonlinear effects on tissue and model substance with emphasis on self-focusing effect. The nature of this effect and its biological consequences are discussed. We have studied how the self-focusing action changes with applied laser power and its effect on various depths ... [Virtual J. Biomed. Opt. 34, 337-339 (2009)]

Yuan Zhao, Yuan Zhang, Xiuli Liu, Xiaohua Lv, Wei Zhou, Qingming Luo, Shaoqun Zeng
The involvement of astrocytes in brain functions rather than support has been identified and widely concerned. However the lack of an effective stimulation of astrocytes hampers our understanding of their essential roles. Here, we employed 800-nm near infrared (NIR) femtosecond laser to induce Ca2+ ... [Virtual J. Biomed. Opt. 17, 1291-1298 (2009)]

Jinyang Liang, Rudolph N. Kohn, Jr., Michael F. Becker, Daniel J. Heinzen
We demonstrate a digital micromirror device (DMD)-based optical system that converts a spatially noisy quasi-Gaussian to an eighth-order super-Lorentzian flat-top beam. We use an error-diffusion algorithm to design the binary pattern for the Texas Instruments DLP device. Following the DMD, a ... [Appl. Opt. 48, 1955-1962 (2009)]

Qinan Li, Baohua Feng, Dongxiang Zhang, Zhiguo Zhang, Huaijin Zhang, Jiyang Wang
A laser diode pumped Q-switched 935 nm Nd-doped Ca_3(NbGa)_2−xGa_3O_12 (Nd:CNGG) laser using a Cr,Nd:YAG crystal as a saturable absorber is demonstrated for the first time to our knowledge. An average output power of 74 mW for 935 nmQ-switched pulses and a repetition rate of 3.788 kHz are ... [Appl. Opt. 48, 1898-1903 (2009)]

Anna Malarski, Benedikt Schürer, Ingo Schmitz, Lars Zigan, Alexandre Flügel, Alfred Leipertz
The imaging and quantification of droplet sizes in sprays is a challenging task for optical scientists and engineers. Laser sheet dropsizing (LSDS) combines the two-dimensional information of two different optical processes, one that is proportional to the droplet volume and one that depends on the ... [Appl. Opt. 48, 1853-1860 (2009)]

Lucas M. Naveira, Benjamin D. Strycker, Jieyu Wang, Gombojav O. Ariunbold, Alexei V. Sokolov, George W. Kattawar
We investigate the controversy regarding violations of the Bouguer-Lambert-Beer (BLB) law for ultrashort laser pulses propagating through water. By working at sufficiently low incident laser intensities, we make sure that any nonlinear component in the response of the medium is negligible. We ... [Appl. Opt. 48, 1828-1836 (2009)]

Yitshak Tzuk, Chana Goren, Alon Tal
A novel scheme for a flashlamp-pumped ultrahigh-gain laser amplifier is presented. It is based on a monolithic slab design achieving a gain of 10^5. The measured ratio between pulse and prepulse output power was 5×10^7. [Appl. Opt. 48, 1819-1827 (2009)]

Yongjie Wei, Baozhen Ge, Yaolin Wei
In general, model-independent algorithms are sensitive to noise during laser particle size measurement. An improved conjugate gradient algorithm (ICGA) that can be used to invert particle size distribution (PSD) from diffraction data is presented. By use of the ICGA to invert simulated data with ... [Appl. Opt. 48, 1779-1783 (2009)]

Simona Ottonelli, Maurizio Dabbicco, Francesco De Lucia, Gaetano Scamarcio
We present a contactless optical sensor based on the laser-self-mixing effect for real-time measurement of linear and transverse displacements of a moving stage. The sensor is able to measure linear displacements of up to 400 mm along the main optical axis while simultaneously estimating ... [Appl. Opt. 48, 1784-1789 (2009)]