We describe an adaptive optical system for use as a tunable focusing element. The system provides adaptive beam shaping via controlled thermal lensing in the optical elements. The system is agile, remotely controllable, touch free, and vacuum compatible; it offers a wide dynamic range, aberration-free focal length tuning, and can provide both positive and negative lensing effects. Focusing is obtained through dynamic heating of an optical element by an external pump beam. The system is especially suitable for use in interferometric gravitational wave interferometers employing high laser power, allowing for in situ control of the laser modal properties and compensation for thermal lensing of the primary laser. Using CO(2) laser heating of fused-silica substrates, we demonstrate a focal length variable from infinity to 4.0 m, with a slope of 0.082 diopter/W of absorbed heat. For on-axis operation, no higher-order modes are introduced by the adaptive optical element. Theoretical modeling of the induced optical path change and predicted thermal lens agrees well with measurement.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/ao.46.002153 | DOI Listing |
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 PDFLight 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 PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!