Asee peer logo

Board 252: Developing Optical Laboratories for Teaching Engineering and Physics

Download Paper |


2023 ASEE Annual Conference & Exposition


Baltimore , Maryland

Publication Date

June 25, 2023

Start Date

June 25, 2023

End Date

June 28, 2023

Conference Session

NSF Grantees Poster Session

Tagged Topic

NSF Grantees Poster Session

Page Count




Permanent URL

Download Count


Request a correction

Paper Authors


Nathan Lemke Bethel University

visit author page

Dr. Lemke is Associate Professor of Physics and Engineering at Bethel University. His teaching interests include upper-level undergraduate engineering and physics courses with laboratory components. His research interests are in the fields of lasers, optical sciences, and atomic devices.

visit author page

author page

Gabriel Michael Hjelle

author page

Zachary Erickson

Download Paper |


We are developing a suite of tools and techniques utilizing optical measurements for teaching a variety of upper-level engineering and physics topics. These designs are intended to be inexpensive and accessible for non-experts. Here we report progress on two tools: a digital holography apparatus for measuring mechanical strain at the micron-level, and a diode laser-based feedback controls system. The holography apparatus has been used once to date for teaching a junior/senior undergraduate mechanical measurements laboratory, while the laser power system will be used in the next semester to teach principles of feedback control systems to electrical and mechanical engineering students. In this paper, we present the designs of the tools and preliminary results from teaching engineering labs and projects with these tools. These tools benefit students by providing a novel alternative to traditional engineering lab apparatus, the opportunity to explore high-precision measurements in a standard undergraduate lab setting, and a starting point for future projects to add new features in the context of project-based learning. We use digital holography for imaging the mechanical deformation of a loaded beam. Our prior work characterized the deformation and related it back to the material’s Young’s modulus; however, that approach suffers from an unclear boundary condition, given that the results typically fell in between the two extremes of rigidly clamped and simply supported boundaries. By measuring with different clamping and loading conditions (i.e. one side clamped, end-loaded vs. center-loaded) we have characterized the boundary condition with greater accuracy, and now can extract a Young’s modulus from this setup that is accurate to within 25%. The goal of the laser feedback controls lab is for students to create a feedback loop that stabilizes the laser power to a constant level. The apparatus uses a printed circuit board and some 3D printed mounts to provide the students with a powered laser, a conditioned photodiode signal that is proportional to laser power, and an area into which various optical filters can be inserted to rapidly adjust the laser power, useful for testing the feedback response of the students’ control algorithm. Either digital or analog control signals are compatible with the hardware; we plan to have students use primarily analog control methods because they mostly closely match the theoretical framework (i.e. Laplace transforms) that is taught in this course. We anticipate teaching with the laser-photodiode system presented side-by-side with the more traditional servo motor system. It is anticipated that having a second physical system to deepen knowledge and develop new intuition will be of benefit to the students’ learning outcomes. This work is supported by the NSF Division of Undergraduate Education.

Lemke, N., & Hjelle, G. M., & Erickson, Z. (2023, June), Board 252: Developing Optical Laboratories for Teaching Engineering and Physics Paper presented at 2023 ASEE Annual Conference & Exposition, Baltimore , Maryland. 10.18260/1-2--42698

ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2023 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015