<title>Assembly processes for micro-optical beam transformation systems for high-power diode laser bars and stacks</title>

Abstract

High power diode lasers (HPDL) have become very attractive as an intelligent tool for direct material processing as well as pump sources for miniaturized solid state lasers and fiber lasers since optical beam transformation systems generate the required beam circularization from the originally highly asymmetric brightness of the output beam. This presentation focuses on reliable microassembling processes to realize micro-optical beam transformation systems for high power diode laser bars and stacks for the efficient coupling of the beam into optical fibers at reasonable costs. The modular semi automatic micro assembly set up realized consists of a six axes alignment system with an accuracy in the submicron range for the three spatial axes as well as microrad for the three rotational axes, a semi-automatic glue dispenser as well as respective grippers and magazines which are necessary for the handling of the micro optical components. The established automation processes for the mounting of the fast axis collimation (FAC) lenses are of particular interest for the assembly of e.g. fiber coupled modules of diode laser stacks whereas more than 20 fast-axis collimations are necessary.

H∞ deflection control of a unimorph piezoelectric cantilever under thermal disturbance

“…For instance, fixing a micro lens at the tip of an optical fiber with 1 µm of relative positioning error or 0,4 µrad of orientation error causes a loss of 50 % of the light flux [3].…”

Robust Feedforward-Feedback Control of a Nonlinear and Oscillating 2-DOF Piezocantilever

“…At this scale, the systems should have accuracy and resolution that are better than one micron. For instance, fixing a microlens at the tip of an optical fiber with 1µm of relative positioning error or 0.4µrad of orientation error may cause a loss of 50% of the light flux [1]. In fact, to reach such high performances, the microrobots, micromanipulators and microsystems are developed with smart materials instead of classical motors (example DC motors) and hinges.…”

Modeling, identification and control of a thermal glue-based temporary fixing system: application to the micro-robotic field

“…The A matrix is constructed from the recurrent equation (6) and from the boundary conditions. The detailed content of the A matrix is not reported in this paper because of its complexity and size.…”

“…FIG. 7 reports the comparison between the results of the numerical model (6) and experimental transient responses of the system using the parameters previously identified. The temperatures resulting from the modeling are close to the experimental temperature then the dynamic model can be used with confidence.…”

“…For example, in the field of material research, very small samples have to be manipulated often in confined space (test equipment) as a Scanning Electron Microscope (SEM) chamber [4]. Most hybrid MicroOpto-Electro-Mechanical Systems (MOEMS) require the manipulation of small lenses or more generally optical microcomponents [5] [6].…”