Automated Misalignment Compensating Interconnects Based on Self-Written Waveguides

Abstract

Abstract-Optical interconnects are the key components for integrated optics to link photonic integrated circuits or to connect external elements such as light sources and detectors. However, misalignment of the optical elements contained and its compensation is a remaining challenge for integrated optical devices. We present a novel method to establish rigid interconnects based on a 2-wavelength self-written waveguide process which automatically compensates for misalignment. We exemplarily demonstrate the capability of our process by writing interconnects between two multimode fibers as well as hot-embossed integrated polymer waveguides and a bare laser diode chip. The coupling efficiency of the interconnects obtained is analyzed with respect to misalignment. We found that coupling losses are as low as 1.3 dB if a lateral misalignment lies within a 10 µm interval, which is achieved by commercially available pick-and-place machines. Our approach is easily combined with high-throughput techniques such as hot embossing and enables low-cost production of interconnects even for mass fabrication in future applications.

Towards fabrication and application of polymer based photonics networks and sensors

“…They feature low optical losses and can be realized at low cost. The most promising approach consists of using two lights fields for their realization, as illustrated in Figure 8 (left), see also [20] for details. In the first step, 5-axis precision stages (Elliott Scientific) were used to butt-couple two optical fibers, for example.…”

“…As a consequence, an optical interconnect forms due to two-wavelength absorption. Compared to the previous approach developed in our group this technique does not require UV laser sources for writing of the waveguides and is also suited to create bent optical interconnects, see [3,20] for details. Also, the writing process can be controlled externally by an additional third light field which is very convenient and easy to implement.…”

Simulation and Experimental Verification of the Thermal Behaviour of Self-Written Waveguides

“…A relatively new concept in this topic include self-written waveguides (SWWs), which have been intensively studied during the last decade [4][5][6]. Moreover, a connection between optical components, which are misaligned with respect to one another, is possible within limitations [7]. An advantage of such types of interconnection is the integrability into a variety of waveguide fabrication processes including hot embossing [8][9][10][11][12][13], photolithography [14,15], or direct laser ablation [16].…”

Simulation of straight and bent self-written waveguides in photopolymer mixture using phenomenological and diffusion models

“…Many experimental and theoretical studies have already been performed to understand the underlying self-writing phenomenon of light in photomonomer as well as in photosensitive material media. [1][2][3][4] An induced change in refractive index occurs within the material as the light propagates through it. Initially, the laser beams diffract freely which is compensated at the later stage by the induced increase in refractive index due to polymerization of the monomer along the propagation axis.…”

“…Such resulting channels are referred as bent SWWs. 4,7 Two theoretical material models are implemented in this work to simulate such straight and bent SWWs. These two material models are then linked with the Crank-Nicholson based Beam Propagation Method (CN-BPM) to obtain the light distributions within the SWWs.…”