Misalignment tolerance analysis of free-space optical interconnects via statistical methods

Abstract

System-level packaging is one of the critical issues that need to be addressed for free space optical interconnections (FSOI) to become useful in desktop systems. The performance of FSOI, e.g., in terms of system bit-error rate, is greatly affected by misalignments in the optical system. Therefore tolerancing, i.e., the ability to analyze and predict the effects of misalignments in the system, is of prime importance to system designers. We introduce an approach in which we study the effects of optical misalignments and other tolerance factors using statistical methods. We use Monte Carlo simulations, design of the experiments, and regression techniques to fit a polynomial equation that expresses the relationship between the system performance and the tolerance factors. This prediction model can be used for design, cost optimization, and quality control purposes. In addition, we perform a sensitivity analysis to determine those tolerance variables that have the greatest effect on system performance.

Quantification of critical alignment parameters for a rotationally-shearing interferometer employing exact ray trace

“…Due to recent stringent requirements in the alignment of optical systems, several proposals for studying and evaluating this procedure have been suggested [34][35][36][37][38][39]. It is well known that ray tracing is a straightforward and useful tool for the alignment and optimization study of optical systems [40][41][42][43].…”

Effects of misalignments in packaging of array-based optical interconnects and processors

“…Using great care, by spending a lot of time, and by using positioners and holders of high accuracy and precision, we can reduce the offsets but we cannot eliminate them totally [4,6,7,13,14]. There can be six possible offsets in the alignment of linear arrays.…”

“…We then determine first order approximations of the effects of these offsets. Monte-Carlo simulation based calculation of the effects of misalignments is discussed in a recent paper [6]. Experimental calculations on the power loss owing to misalignments are reported in [7].…”

Integration of precisely aligned lenslet arrays with waveguide arrays

“…4 However, critical alignment is still required at the laser-lens, lens-waveguide, and lens-detector interfaces. 5 Therefore, coupling lenses are often integrated directly with the laser source and the detector. It is also desirable to integrate the coupling lenses with the waveguides during fabrication.…”