A pulsed, two-beam, thermal lensing experiment was performed to determine the concentration of aqueous solutes above the critical point of water. Despite a very significant mirage effect due to thermal gradients in the cell and absorption by water itself, the thermal lensing signal strength for aqueous benzoic acid in supercritical water was found to be linear with concentration in the sub-millimolar range. Although thermal lensing experiments in aqueous media are notoriously insensitive, the sharp density gradient near the critical point considerably improves the signal intensity. In this study a short-pulse pump 266 nm YAG laser and continuous low-power probe Ar ion beam were both focused into a supercritical water cell, giving a lensing signal whose strength could be maximized by changing the overlap of the two beams.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jp066107b | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Very high-average optical enhancement cavities (OECs) are being used both in fundamental and applied research. The most demanding applications require stable megawatt level average power of infrared picosecond pulses with repetition rates of several tens of MHz. Toward reaching this goal, we report on the achievement of 710 kW of stable average power in a two-mirror hemispherical optical enhancement cavity.
View Article and Find Full Text PDFUltra short pulse Ti:sapphire lasers, crucial for most demanding applications, have traditionally been complex and costly due to their pump sources. GaN-based laser diodes offer new prospects for pumping, yet challenges persist in achieving sufficient Ti:sapphire output power and beam quality. We introduce what we believe to be a novel approach using pulsed blue laser diode pumping of a Ti:sapphire amplifier.
View Article and Find Full Text PDFArticle Synopsis
- The study explores how thermal bonding and concave end faces impact the performance of 795 nm laser diodes (LD) when used to pump Tm:YAP crystals.
- Concave end faces help to counteract thermal lensing effects, allowing for higher power output, reaching 42.5 W with a slope efficiency of 47.4% and optical-optical conversion efficiency of 41.6%.
- Compared to flat bonding rods, the concave design improves the maximum output power and efficiencies, demonstrating its effectiveness in enhancing heat dissipation and laser performance.
Bright compact ultrabroadband source by orthogonal laser-sustained plasma.
Light Sci Appl
September 2024
School of Instrumentation and Optoelectronic Engineering, Beihang University, Beijing, 100191, China.
Laser-sustained plasma (LSP) source featuring high brightness and broadband spectral coverage is found to be powerful in various fields of scientific and industrial applications. However, the fundamental limit of low conversion efficiency constrains the system compactness and widespread applications of such broadband light sources. In this paper, we propose an innovative orthogonal LSP to break through the conversion efficiency limitation.
View Article and Find Full Text PDFUltrafast laser pulse filamentation in the air can be used for remote sensing by exciting a characteristic optical emission, which is usually referred to as filamentation-induced breakdown spectroscopy. In environments that impede light propagation, such as fog, haze, or clouds, scattering makes it challenging to propagate laser beams and retrieve generated optical signatures. We demonstrate the effectiveness of laser filamentation for simultaneously clearing the path for intense femtosecond pulse propagation in a highly scattering medium, generation of luminous plasma on a solid target, and counter-propagation of a characteristic spectroscopic signal over a cleared channel along the filament path.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!