DELFT UNIVERSITY OF TECHNOLOGY
Department of Precision and Microsystems Engineering
09 February 2016
To:
the staff of PME
the students of PME
Subject:
PME-Final MSc presentation
We are pleased to invite you to attend the PME- Final MSc presentation at:
Thursday 28 August 2014, 13.30 hrs
Studio 23/24 at IO
Mekelweg 2
2628 CD DELFT
13.30 hrs
A. Zondervan, specialisation: Mechatronic System Design
Title:
Design of a Free-space and Single-mode Fiber Coupling Device
A trend in metrology is the development of optical sensors. These types of sensors benefit of the minimum
interaction of light with standard noise sources (e.g. electric fields) and the high carrier frequency (THz) allowing for more accurate measurements than with conventional electronic sensors. The use of a laser and
an optical fiber to guide the laser light in such metrology applications can easily be motivated.
In order to facilitate the coupling of a laser beam (∅10^−3 [m]) into a single-mode fiber (∅10^−6 [m]), a
device is needed. Even though such devices are available today, a clear demand can be seen for a device
that reduces alignment effort and increases optical efficiency to a minimum of 30% or preferably more.
Realizing established firms designed and build the non-satisfactory devices available today motivates an indepth study of the optics involved to translate the requirements for a free-space-to-fiber in-coupling device
into specifications.
An analytical method is presented that allows the user to assess the performance of both theoretical and
realized coupling devices based on a single lens principle. The method and assumptions regarding initial
alignment are used to assess devices available today, which all proved lacking in specifications or even their
basic principles. A new control principle is designed, prototype build and analyzed in accordance with this
method.
Summing up the results of the report, it can be concluded that a working prototype has been build that
demonstrated in-coupling at the expected theoretical maximum efficiency (≥ 86%). Regarding the
objective, up to 87.8% of the optical power produced by the laser is coupled in to the fiber. The prototype
is able to maintain coupling over time with a transmittance efficiency higher than 63.9% for at least 32
hours. Moreover, a layman is able to use the device reaching an efficiency higher than fifty percent.
The presentation will be given in English.
13.50 hrs
Debate
14.00 hrs
End
Attending colloquia is an obligatory part of the curriculum of PME.
The presence of other people who are interested will be appreciated.