Modeling diffraction and imaging of laser beams by the mode-expansion method

2019

IJECE

We introduce convenient model and an optimization scheme to optimize the signal-to-crosstalk ratio (SCR) in a free space optical interconnects (FSOIs) system that uses microlenses with finite circular apertures. In this model, we consider both the stray light crosstalk and the crosstalk due to the diffraction at the microlens apertures to evaluate the SCR. Using cylindrical form of Collins diffraction integral and the Laguerre–Gaussian (LG) beam model, we derive an approximate closed form formula for the optical field of a multimode LG beam propagating through circular apertured FSOIs by expanding the hard edge circular aperture function of the microlens in terms of complex Gaussian functions. The analyses indicate that the size of the detector is an important factor to optimize the SCR for both the apertured and the unapertured misaligned FSOIs system. The effect of higher order mode of the laser source on the SCR is also considered.

“…The (7) gives the optical field distribution at the output plane for a linear optical system in a cylindrical coordinate system with slight misalignment.…”

Section: Optical Field In a General Misaligned First Order Optical Symentioning

confidence: 99%

Section: Optical Field In a Misaligned Fsois Without Aperturementioning

confidence: 99%

See 1 more Smart Citation

Crosstalk in misaligned free space optical interconnects: modelling and simulation

2019

IJECE

“…The light sources array is placed at a distance 1 d from the microlens array. The distance between the detector array and the microlenses array is 2 d . To find the field distribution at the detectors plane we use the diffraction integral formula for an aligned optical system in cylindrical coordinate system assuming paraxial approximations.…”

Section: Optical Field At Detector Planementioning

confidence: 99%

Performance Analysis of Paraxial Free Space Optical Interconnects System that Uses Bessel Beams and Micro-Lenses with Circular Apertures

2014

IJCEE

Abstract-In this article the performance of microlens based free space optical interconnects system under paraxial approximations is considered. Instead of using Gaussian beams, we propose the use of the Bessel beams to transfer the information. The performance of the proposed system is evaluated and compared with that of Gaussian beams using the signal to crosstalk ratio as the system metric. It is shown that the optical system that uses Bessel beams gives superior results when used in applications with large interconnects length.Index Terms-Bessel beams, diffraction, free space optical interconnects, gaussian beams, non-diffracting beams.

“…In these FSOIs systems light sources with Gaussian profiles are usually used. The crosstalk in these Gaussian-based systems is prominent and careful design is required to reduce its effect [6][7][8][9]. One interesting method to reduce the diffraction, particularly in board-to board applications with large interconnect distance, is the use of non-diffracting Bessel beams [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Bessel Beams and Gaussian Beams as information carriers in free space optical interconnects systems: A comparison study

2019

IJECE

We introduce a comparison study for the performance of a lens-based free space optical interconnects system assuming Bessel Beams and Gaussian Beams as information carriers. The optical field at the detector plane was derived for the two beam profiles. In both cases the expressions for the output optical filed are expressed in terms of complex Gaussian functions. The performance of the system for the two beams is evaluated and compared. Using simulation results we show that the use of Bessel beam gives superior results to that of using Gaussian beam for large interconnects distance.