<title>Assembly of fast-axis collimating lenses with high-power laser diode bars</title>

Abstract

The assembly of fast-axis collimating lenses (FAC-) with high power laser diode (HPLD) bars and stacks is discussed. FAC-lenses are cylindrical lenses of high numerical aperture (NA.> 0.5) and short focal length (200 .tm..1 mm) for the collimation of the strongly divergent radiation emitted perpendicular to the active region of a high power laser diode bar. These FAC-lenses are necessary for all kind of beam transformation systems using HPLD bars and stacks. The lenses have to be fixed at the heat sink ofthe laser diode bar with an accuracy of < 0.3 im and for special transformation systems with a defmite tilt of 1 ..2°and an accuracy of better than mrad. In most cases an active assembly of the whole beam transformation system is necessary. Here we propose another approach. . A master system is assembled in a traditional way. The diode bar and the fixed FAC-lens are removed from the system.. The intensity distribution behind the FAC-lens in connection with conventional cylindrical lens for slow axis imaging is measured and compared to a theoretical system design. . Stops are fabricated according to the intensity distribution and placed in a defmite distance to the laser diode bar.. FAC lenses are mounted in front of a single diode bar by maximizing the total power passing the stop system. With the help of this approach a first step towards a semi-automated assembly is done for fiber coupling of a laser diode bar into a 200 tm multimode optical fiber ofN.A.= 0.2. The system requires a slightly tilted FAC-lens of very short focal length (300 .tm) and hence a high accuracy of the lens assembly.

Simulation and Experimental Study of Laser Hammering for Laser Diode Packaging

“…Currently, the Nd:YAG laser welding technology is being widely used in opto-eletronic packaging because of its many outstanding advantages such as inherit attributes of strength, cleanliness, long term reliability, non-contact process, low heat distortion, repeatability, ability to automate, etc. During the last two decades, a lot of companies, universities, institutes have done many research works on laser welding for optical components packaging due to its outstanding advantages [1]- [10], such as Jang [1], Adept [4], Mueller [5], Coyle [6], Gohji [7], Possner [8], Lin [9], and Hsu [10], [18]. However, one particular drawback is the so-called post-weld-shift (PWS).…”

Lateral Flow through a Parallel Gap Driven by Surface Hydrophilicity and Liquid Edge Pinning for Creating Microlens Array

“…Obviously by using a template arrayed with parallel gratings, the proposed process can also be easily used for generating MLA with a cylindrical curvature, which may find applications such as collimating high-power diode lasers, homogenizing and transforming the laser beam, organic light-emitting diode (OLED) panel, etc. Figure b shows a MLA with a concave cylindrical curvature (i) and its duplicate as a MLA with a convex cylindrical curvature obtained by micromolding (ii).…”