• Webb, A. S.
• Smith, Peter G. R.
• Gates, James C.
• Sahu, Jayanta Kumar
• Holmes, Christopher
• Ambran, S.

Abstract

A novel flat-fiber platform is presented for fabricating integrated optical multimode interference (MMI) devices. Fabrication is achieved by modifying a standard optical fiber drawing process and applying a micromachining technique. The fabricated structure consists of an MMI region within the flat-fiber that is defined by micromachined trenches, illustrated in Figure 1(a). A 1×3 splitter has been demonstrated, with a spatial output mode that be tuned by placing refractive index oils within the micromachined trenches.<br/> MMI devices have been demonstrated in different planar platforms such as silicon-on-insulator and silica-on-silicon. However, many of these materials are potentially expensive, high loss or have a complex fabrication process. The desire to have a fiber-like platform, capable of supporting multiple waveguides in a planar format, led us to develop a novel silica optical flat-fiber technology. This allows us to overcome the limitations of existing planar technologies by offering a low cost, low loss substrate with fiber-like flexibility, long lengths and the ability to make integrated devices. The flat-fiber substrate is fabricated using standard silica fiber fabrication but differs by collapsing the preform during the fiber drawing stage by using a vacuum. The trenches of the device were diced using an ultra-precision micromachining technique.

Topics

• impedance spectroscopy
• Silicon
• drawing