Last modified: 2018-07-19
Abstract
Optical fiber micro-collimators are Optical fibers equipped with microlenses, become essential end components in the field of optoelectronics. They ensure the transfer of light energy in a connection. Several studies have been proposed in order to optimize this optical coupling and have led to the proposal of various solutions. However, it remains difficult to increase the coupling efficiency due to the difference between the mode field diameters (MFD) of the laser diode and the optical fiber. The microlenses at the end of the fibers are using to increase the coupling efficiency. The microlenses can have different surface morphology to modulate the incident waist of the laser diode (LD) and transmit it into the SMF. This provides better-collimated beams for coupling applications.
In this work, we will represent the Manufacturing Methodology of the micro-collimator involves etching a conical microcavity at the end of an optical fiber. The selective etching [1] process produces a concave cone centered on the axis of the core of the fiber [2]. We will highlight the peculiarities of the process. In the microcavity is inserted a quantity of PDMS (Polymer of good optical properties). The micro-collimators obtained are equipped with microlenses [3].
Depending on the amount of PDMS, different radii of curvature (focal) are obtained.
The second part of this work is dedicated to the coupling of a laser diode to a spherical microlens in PDMS on the end of a single mode fiber (SMF) (9 / 125m, telecom). The light transmission through a micro-collimator was digitally analyzed in 2D using the COMSOL Multiphysics finite element software.The simulation results shows the optical focusing characteristics (Waist, Working distance) and shows optical coupling performance.