Fabrication of an integrated optical system in glass using laser assisted manufacturing

Fabrication of an integrated optical system in glass using laser assisted manufacturing

Kategorien Konferenz (reviewed)
Jahr 2021
Autoren Reitz, B.; Hoffmann, G.-A.; Gottwald, S. N.; Overmeyer, L.
Veröffentlicht in Proceedings Volume 11815, Novel Optical Systems, Methods, and Applications XXIV; 118150B

While glass is an ideal material for optics, only a few microprocessing technologies are available. These technologies are usually limited regarding precision and freedom of design. A novel glass micromachining process is Laser Induced Deep Etching (LIDE). Without generating micro-cracks, introducing stress or other damages, it offers the possibility to precisely machine many types of glass. A broad range of features such as high-aspect ratio through holes, cutouts and slits in glass are available. In this work, LIDE is used to produce glass carrier substrates for integrated optical systems. Due to transmission characteristics and refractive index, the glass can be used as optical cladding for integrated polymer optical waveguides (refractive indices < 1.45). Cavities in glass, which can have different cross-sections e.g. u- or v-shaped, are filled with photoactive material by a doctor blade and function as an optical waveguide core. An additional approach examined in this work is the integration of optical fiber into v-shaped cavities. The system uses bare die laser diodes as transmitters and photo diodes as receivers bonded in front of the waveguide. LIDE technology allows to passively align the manufactured optical waveguide in front of the light source and detector due to mechanical features in the carrier substrate itself, eliminating the need for time-consuming and complex active alignment processes. This paper shows geometrical characteristics of waveguides and cavities, with a particular focus on surface roughness and subsequent filling ratio of the optical waveguide. Furthermore, the relative intensity distribution in the waveguide is presented and analyzed.

DOI 10.1117/12.2596376