Proceedings Article | 12 March 2024
KEYWORDS: Semiconductor lasers, Collimation, Reliability, Scientific research, Laser applications, High power lasers, Design, Biomedical applications, Packaging, Laser bonding
808nm Quasi-Continuous Wave (QCW) Laser Diode arrays (LDAs) have found a wide range of applications in medical, scientific research, defense, surveillance and solid-state laser pumping, printing and others. As a result, the design varieties and upgrades of such products have emerged as prominent topics in the current discourse. Through a compact structural design and optional independent bar beam shaping, we achieve high-power, high emission density, narrow spectral width, excellent uniformity, and consistent pulsed laser output. The entire product series, namely G-stack and C-stack, allowing for customization of pitch, number and type of bars, output power, wavelength range, overall dimensions, and beam profile according to customer requirements. This product features a highly reliable gold-tin bonding packaging, which ensures the stability and durability of the laser system over a long service life. These products demonstrate reliable operation up to 20% duty cycle. This article primarily focuses on a sandwich structure as the basic building block for further packaging. Here, eight sandwiches with a pitch of 1.7mm form one subunit, and three units are vertically arranged in a 3×8, 24-bar array configuration. Under a 3% duty cycle test, by bar selection, the output wavelength could be achieved within a range of 808nm±1nm, with a FWHM of less than 3.5nm and peak power exceeding 11 kW pulsed. Additionally, this design showcases exceptional reliability, accumulating over 7000 hours of reliability test data under various conditions. Optically, precise collimation is achieved by employing not only best collimation alignment to the specified divergence using from simple fibers to aspheric cylinder lenses, but also specific pointing angles for each bar's fast axis, resulting in outstanding beam uniformity of 95%. These high-power and high-uniformity array products find significant applications in scientific research fields, where the uniform laser output yields substantial benefits in crystal absorption and pumping efficiency. This design holds also great potential and benefits in the field of hair removal, serving to the increasing demand and widespread acceptance of laser-based epilation.
