Analysis of optical channel cross talk for free-space optical interconnects in the presence of higher-order transverse modes

Abstract

-We analyse the effect of crosstalk noise on the performance of free space optical interconnects (FSOIs). In addition to "diffraction-caused" crosstalk, we consider the effect of "stray-light" crosstalk noise which, to the best of our knowledge, has not been addressed previously. Simulations were performed on a microlens based FSOI system using the modal composition and beam profiles experimentally extracted from a commercial Vertical-Cavity Surface-Emitting Laser. We demonstrate that this crosstalk noise introduces significant degradation to interconnect performance, particularly for multi-transverse mode laser sources. A simple behavioural model is also developed which accurately approximates the crosstalk noise for a range of optical sources and interconnect configurations.

A Massively Parallel Imaging System Based on the Self-Mixing Effect in a Vertical-Cavity Surface-Emitting Laser Array

“…Also, the potential effects of optical crosstalk with the integrated VCSEL array can be minimized by an optimized design of the optical system using an array of micro lenses. Similar approach has been successfully implemented earlier for minimizing the crosstalk between channels in VCSEL based free-space optical-interconnects [34], [35].…”

Parallel self-mixing imaging system based on an array of vertical-cavity surface-emitting lasers

“…On the other hand, the potential effects of optical crosstalk with the monolithically integrated VCSEL array can be minimized by an optimized design of the optical system using an array of micro lenses. A similar approach has already been successfully implemented for minimizing the crosstalk between channels in VCSEL based free-space optical-interconnects 37,38 and the authors believe that this will lend the proposed system to a wide variety of sensing applications.…”

Minimising crosstalk in microchannel free-space optical interconnects with the presence of higher order modes

“…We now consider another source of optical crosstalk, introduced by [17]. Again, we consider an arbitrary channel within the microchannel architecture, depicted by Fig 1.…”

“…Following a number of studies [14][15][16], diffraction-caused crosstalk noise is modelled as the power incident on unintended receiver microlenses due to diffraction at the transmitter microlenses and the spread of the laser beam between the transmitter microlens array and the receiver microlens array. Stray-light crosstalk noise [17] is the fraction of the emitted power imaged by the neighbouring transmitter microlens to other channels, possibly far from the intended one. This paper investigates the effects of both forms of crosstalk noise on the performance of FSOI system.…”