Homogenous concept for the coupling of active and passive single-mode devices by utilizing planar gradient-index lenses and silicon-V grooves

1998

SPIE Proceedings

In the field of optical interconnection research, the topic perhaps closest to widespread applications is the realization of optical board to board and chip to chip interconnections [1]. The inherent limitations of electronic interconnects regarding bandwidth and electromagnetic interference are overcome by waveguide, fiber, or free space optics. With free space optics additionally the high interconnect density ofoptical imaging can be employed. One ofthe basic problems is the addressing of emitted signals to the intended detector.The concept of folding a free-space optical system into a thick transparent planeparallel substrate, was proposed by Jahns and Huang in 1989 [2]. Planar optics, also known as substrate-mode optics, fully employs the three dimensional nature of light propagation and also the fabrication methods known from integrated circuit manufacturing can be adopted. In addition to that the advantage ofthese technologies are compact packaging and simple alignment ofthe optical and electronical elements. The problem involved in folding optical light paths for imaging of extended data fields is the demand for good off-axis imaging properties ofthe optical elements. Besides diffractive solutions i.e. DOEs or CGHs [3] refractive optics offers the possibility for wavelength multiplexing since the wavelength dependence is only due to material dispersion. For off axis imaging in a folded zig-zag-path the optical system also has to be corrected by special astigmatic components. ApproachIn this paper we present an optical motherboard scheme using only planar refractive micro lenses in a folded light-pipe system ( fig. 1 ). For imaging of extended data fields we use a planar micro lens with spherical symmetry in reflection mode. As a matter of principle all non symmetric wave aberrations, such as astigmatism, distortion and coma can be excluded and only curvature of field has to be considered for the system design. We have recently proposed and demonstrated the fabrication of planar micro lenses with nearly ideal semi-spherical symmetry by a field assisted ion exchange process in glass [4]. To avoid wavelength dependence in the system, commonly introduced by using CGHs for addressing input and output channels, additional planar micro lenses were placed respectively as field lenses. For a certain pixel in the input plane the field lenses act as a prisms, which specify the angle of the light path through the system. So with the choice of the position in the input plane an arbitrary position in the output plane can be addressed. As shown in figure 1 other output planes are addressable with this system as well.

Section: Fabrication Methodsmentioning

confidence: 99%

Optical motherboard: a planar chip-to-chip interconnection scheme for dense optical wiring

1998

SPIE Proceedings

“…Figure 11 shows the distribution of the electrical drift field using a small mask window. The quality of these microlenses has been demonstrated in the application of coupling of monomode fibers [7]. Due to the distribution of the electrical drift field, the index distribution is semispherical and steplike.…”

Section: Field Assisted Ion Exchange For Higher Na Valuesmentioning

confidence: 98%

<title>Realization of refractive continuous-phase elements with high design freedom by mask-structured ion exchange</title>

2001

SPIE Proceedings

We suggest a new technique for fabricating a wide class of continuous refractive optical elements in glass by combining the technique of ion exchange with high precision structuring of metal masks. We call this technique mask structured ion exchange (MSI). We have demonstrated the potential of this method by fabrication of rectangular shaped microlenses with low numerical aperture for Hartmann-Shack wavefront sensing applications. The lenses, positioned on a 400 µm raster, had a fill factor of 100 %, a focal length of 33 mm and diffraction limited performance. Due to the special fabrication conditions, the lens shape, position and even the focal length can be varied spatially within one substrate. For realization of a high aperture microlens array by field assisted exchange process we could reduce proximity effects between adjacent mask apertures by MSI.

“…The quality of these micro lenses has been demonstrated in the application of a connector of single mode fibers [15]. The basic concept of the connector is shown in figure 21.…”

Section: With Diffraction Limited Performancementioning

confidence: 99%

Applications and potential of the mask structured ion exchange technique (MSI) in micro-optics

Gradient Index, Miniature, and Diffractive Optical Systems III

2003

The mask structured silver sodium ion exchange in glass (MSI) is a powerful tool for the realization of high precision refractive micro optical GRIN components. Commonly the distribution of the silver ions in GRIN elements and thus the index distribution is determined by the laws of thermal diffusion. By the use of a structured metal mask, which defines the areas of contact between the glass and the silver salt melt, an additional degree of freedom in optical design is introduced. A photolithographic pattern generator provides the accuracy of the mask structure to realize wave front optimized micro lens arrays with 100% fill factor in Cartesian, hexagonal and also in nearly any other arbitrary geometrical arrangements for several applications such as high precision Shack-Hartmann systems.In this paper we want to discuss the potential and limits of this technique. We report on the family of optical functions, which can be realized with MSI. Furthermore we give an overview over the actual applications.