InP/InGaP quantum-dot SESAM mode-locked Alexandrite laser

A semiconductor saturable absorber mirror (SESAM) passively mode-locked Alexandrite laser was demonstrated. Using an InP/InGaP quantum-dot saturable absorber mirror, pulse duration of 420 fs at 774 nm was obtained. The laser was pumped at 532 nm and generated 325 mW of average output power in mode-locked regime with a pump power of 7.12 W. To the best of our knowledge, this is the first report of a passively mode-locked Alexandrite laser using SESAM in general and quantum-dot SESAM in particular

High power Nd:YVO-KGW conical refraction laser

We have demonstrated the highest conical refraction (CR) laser output power to date by placing a CR crystal inside of a diode-pumped Nd:YVO laser cavity. The CR crystal did not have a significant influence on laser output power as well as efficiency. The CR laser produced the maximum output power of 3.68 W with the slope efficiency of 42 % and opticalto- optical efficiency of 34 %. Therefore, this approach could be an attractive pathway for further power scaling of the CR lasers

Conical refraction lasing in a Nd:YVO4 laser with a conerefringent KGW element

A conical refraction (CR) laser based on a separate gain medium (Nd:YVO4) and an intracavity CR element (KGW) was demonstrated. The decoupling of the gain and CR media enabled the laser to produce a well-behaved CR laser beam with excellent quality, while reducing the complexity of the pumping scheme. The proposed laser setup has the potential for power scaling using the efficient diode pumping approach and the properties of the generated CR beam are independent from the laser gain medium

Diode-pumped passively mode-locked ultrashort pulse solid-state lasers

Available from British Library Document Supply Centre- DSC:DXN064246 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Compact Diode-Pumped 946 nm Nd:YAG Laser with Good Beam Quality

A continuous-wave (CW), high-power, quasi-three-level Nd:YAG laser operating at 946 nm is reported. The beam quality of the laser is greatly improved. The laser consists of a composite Nd:YAG rod end pumped by a fiber-coupled diode laser inside a simple concave-plane cavity. At an incident pump power of 31 W, a maximum CW output of 9.98 W was obtained at 946 nm, with a beam quality factor of M2~5. The corresponding optical-to-optical efficiency was 32.2% with respect to the incident pump power. To the best of our knowledge, this is the highest output power at 946 nm with such a beam quality ever generated by diode-pumped Nd:YAG laser with bulk crystals

Coherent two-photon absorption spectroscopy of the Raman-active KGd(WO4)2 crystal

We report on the systematic open-aperture Z-scan characterization of the two-photon absorption properties in one of the most efficient solid-state Raman frequency shifters, the crystal potassium gadolinium tungstate [KGd(WO4)2]. The two-photon absorption coefficient was determined in the 370-600-nm wavelength range, with the highest value found to be ~1.9 cm/GW at 370 nm. Nonlinear losses are crucial in determining the conversion efficiency of the stimulated Raman scattering process when it is excited with ultrashort laser pulses with photon energy exceeding half of the bandgap. In addition, the results were analyzed within the context of a simple two-parabolic-band theoretical model to yield an effective bandgap energy value for the crystal

Efficient Raman shifting of high-energy picosecond pulses into the eye-safe 1.5-µm spectral region by use of a KGd(WO4)_2 crystal

We report an efficient transient stimulated Raman conversion of high-energy picosecond pulses at 1350 nm into the eye-safe 1500-nm wavelength range by use of a KGd(WO4)_2 crystal. The conversion efficiency into either 1503- or 1537-nm radiation (767- or 901-cm^-1 Raman modes, respectively) is measured to be ~10% in a single-pass configuration. The transient Raman gain coefficient is found to be ~0.8 cm/GW. Simultaneous generation of multiple Raman lines is also observed

TZee: Exploiting the lighting properties of multi-touch tabletops for tangible 3d interactions

Manipulating 3D objects on a tabletop is inherently problematic. Tabletops lack a third degree of freedom and thus require novel solutions to support even the simplest 3D manipulations. Our solution is TZee – a passive tangible widget that enables natural interactions with 3D objects by exploiting the lighting properties of diffuse illumination (DI) multitouch tabletops. TZee is assembled from stacked layers of acrylic glass to extend the tabletop’s infrared light slightly above the surface without supplemental power. With TZee, users can intuitively scale, translate and rotate objects in all three dimensions, and also perform more sophisticated gestures, like “slicing ” a volumetric object, that have not been possible with existing tabletop interaction schemes. TZee is built with affordable and accessible materials, and one tabletop surface can easily support multiple TZees. Moreover, since TZee is transparent, there are numerous possibilities to augment interactions with feedback, helpful hints, or other visual enhancements. We discuss several important design considerations and demonstrate the value of TZee with several applications

Nonlinear optical microscopy in decoding arterial diseases

Pathological understanding of arterial diseases is mainly attributable to histological observations based on conventional tissue staining protocols. The emerging development of nonlinear optical microscopy (NLOM), particularly in second-harmonic generation, two-photon excited fluorescence and coherent Raman scattering, provides a new venue to visualize pathological changes in the extracellular matrix caused by atherosclerosis progression. These techniques in general require minimal tissue preparation and offer rapid three-dimensional imaging. The capability of label-free microscopic imaging enables disease impact to be studied directly on the bulk artery tissue, thus minimally perturbing the sample. In this review, we look at recent progress in applications related to arterial disease imaging using various forms of NLOM.Peer reviewed: YesNRC publication: Ye