We have designed, fabricated, and characterized a micro-optical beam-shaping device that is intended to optimize the coupling of an incoherent, linearly extended high-power diode laser into a multimode fiber. The device uses two aligned diffractive optical elements ͑DOEs͒ in combination with conventional optics. With a first prototype, we achieved an overall efficiency of 28%. Straightforward improvements, such as antireflective coatings and the use of gray-tone elements, are expected to lead to an efficiency of approximately 50%. The device is compact, and its fabrication is suited for mass production at low cost. This micro-optical device, used in a range-finder measurement system, will extend the measurement range. In addition to the direct laser writing technique, which was used for fabrication of the DOEs of the prototype, we applied two other technologies for the fabrication of the micro-optical elements and compared their performance. The technologies were multiple-projection photolithography in combination with reactive-ion etching in fused silica and high-energy beam-sensitive glass gray-tone lithography in photoresist. We found that refractive-type elements ͑gray tone͒ yield better efficiency for large deflection angles, whereas diffractive elements ͑multilevel or laser written͒ give intrinsically accurate deflection angles.

Abstract:We present a comparison of three different technologies for the fabrication of microoptical elements with arbitrary surfaces. We used direct laser writing, binary mask lithography in combination with reactive ion etching, and graytone lithography.

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Abstract-We present the first steps executed to space qualify an assembly technique for miniaturized optical components that already demonstrated its maturity for the ground segment. Two different types of demonstrators have been manufactured and submitted to various tests: endurance demonstrators placed in simulated environment reproducing strong space environmental constraints that may potentially destroy the devices under test, and a functional demonstrator put in operational conditions as typically found in a satellite environment. The technology, the realized demonstrators and the results of the tests are reported.