Session S4A OPTICS FOR SCIENTISTS AND ENGINEERS Orven F. Swenson1 , David A. Rogers2 , Floyd M. Patterson3 , and Andres Campiglia4 Abstract  Faculty members from three departments at North Dakota State University (Physics, Electrical and Computer Engineering, and Chemistry) have cooperated to develop a joint program in optical science and engineering. An option in Optical Engineering has been established within the major in Electrical Engineering and an option in Optical Science and Engineering has been established within the major in Physics. A core course, “Optics for Scientists and Engineers,” was introduced in Fall Semester, 2001 and is being offered again in 2002. This new course provides students with the fundamentals necessary to enable them to successfully apply optics in their respective majors. Students learn applied optics through a sequence of multidisciplinary laboratory experiences. This course was adapted from a similar course in the Optical Science and Engineering Program, New Jersey Institute of Technology. During Fall Semester 2001, seventeen students successfully completed the course. Interest in the course offering in the fall of 2002 is high. In general the course has awakened an interest in optics among engineering and science majors.

or first-year graduate course with prerequisites of University Physics II (Electricity and Magnetism) and the corresponding level of calculus. Offering three credits, this one-semester course consists of 30 hours of lecture and 45 hours in the laboratory. The schedule is as follows: (a) first two weeks: three one-hour lectures per week; (b) ten weeks: two one-hour lectures and one three-hour lab per week; (c) three weeks: laboratory five hours per week to work on major-related experiment; and (d) one week: students present results during three classroom hours. Lectures are based on Eugene Hecht’s Optics [3] to provide the background required for performing the experiments. The laboratories are scheduled in three-hour blocks. Students are paired to maximize their hands-on experience. A graduate student teaching assistant is present in the laboratory for all the groups. During the first offering of the course, a member of the faculty teaching team was also present during each laboratory session. In the next section the position of this course in the curriculum along with two more goals for the course will be considered.

Index Terms  electrical engineering, laboratory course, optics, physics.

OPTICAL SCIENCE AND ENGINEERING OPTIONS

INTRODUCTION A rigorous course in applied optics has been developed at North Dakota State University (NDSU) through the cooperation of three departments at the University: Physics, Electrical and Computer Engineering, and Chemistry. This course was modeled after a course that originated at New Jersey Institute of Technology in the Optical Science and Engineering Program [1]-[2]. The new course, Physics/ECE 411/611, Optics for Scientis ts and Engineers, was introduced in Fall Semester, 2001 and is being offered again in 2002. The primary goal of this new course is to provide students with the fundamentals necessary to enable them to successfully apply optics in their respective majors. It is a course in which students learn applied optics through a sequence of multidisciplinary laboratory experiences. This is accomplished through hands-on use of state-of-the-art equipment to experience and understand the most important concepts and phenomena of optics (including fiber optics). The course is open to students in engineering and science who have the appropriate backgrounds. This is a senior-level

Optics plays a significant role in many areas of science, engineering, and medicine since it can be both a conveyor and sensor of information and energy [4]-[5]. Since 1999 NDSU faculty members from the College of Engineering and Architecture and from the College of Science and Mathematics have been developing a joint program in optical science and engineering. In Engineering and Architecture, an option in Optical Engineering has been established within the major in Electrical Engineering. In Science and Mathematics, an option in Optical Science and Engineering has been established within the major in Physics. Aside from this option, Physics already has an option in engineering physics within its major in Physics. The option in Optical Engineering is the eighth option available to majors in Electrical Engineering. The other options are Biomedical Engineering, Communication and Signal Processing, Computer Engineering, Control Engineering, Electromagnetics, Electronics and Microelectronics, and Power Systems. Students in the Department of Electrical and Computer Engineering can also major directly in Computer Engineering. These physics and ECE majors (i.e., all options) lead to the B.S. degree.

Partial support for this work was provided by the National Science Foundation’s Course, Curriculum and Laboratory Improvement Program under grant DUE - 0088516. 1 Orven F. Swenson, Dept. of Physics, North Dakota State University, Fargo, ND 58105, [email protected] 2 David A. Rogers, Dept. of Electrical and Computer Engineering, North Dakota State University, Fargo, ND 58105, [email protected] 3 Floyd M. Patterson, Dept. of Electrical and Computer Engineering, North Dakota State University, Fargo, ND 58105, [email protected] 4 Andres Campiglia, Dept. of Chemistry, North Dakota State University, Fargo, ND 58105, [email protected]

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Session S4A ECE Department optical engineering students customarily take an additional nine to 13 credits in modern and optical physics and nine to 12 credits in optical engineering. The new course in optics for scientists and engineers is considered to be an optical engineering course for the ECE Department students. These options will provide new opportunities for ECE students and Physics students to obtain optical engineering positions in industry while also equipping them for graduate studies in this area. This should also increase the interdisciplinary work between the departments. One example will be the performance of capstone projects that are joint activities of Physics and the ECE Department. As stated earlier, the primary objective of the optics teaching laboratory is to benefit students by providing optics tools and knowledge to take back to their respective disciplines. The course includes a major-related optics experiment to contribute toward success in this objective. A secondary goal is to incorporate components of the optics teaching laboratory into the currently offered optics and optical electronics courses that do not presently have laboratory components. This facility will serve as the laboratory for ECE 457/657, the Department of Electrical and Computer Engineering course in optical signal transmission (based on [6]). These are required courses for the optics options described above. Future development of the optics options will involve the incorporation of extensive hands-on experience in most optics courses. A tertiary goal is to use the equipment to interest top regional high school juniors and seniors in science and engineering careers. This is being done through the annual North Dakota Governor’s School held for six weeks on the NDSU campus for a select group of 20 high school students. This outreach is particularly important for students from small rural high schools that have little or no laboratory equipment and often do not offer physics courses. The laboratory experiments are modeled on those developed at New Jersey Institute of Technology [1]-[2] and also make use of some experiments developed by Newport Corporation [7]. The University has provided a large room on the first floor of the building that houses the Physics Department. The new laboratory stations that have been developed are expected to stimulate the development of additional advanced optics laboratory courses.

ORGANIZATION OF THE COURSE Our approach was to offer an upper level undergraduate course targeted to the full spectrum of science and engineering students. This goal limited us to a threesemester-hour course in order for students to fit it into their curricula. A three-hour optics lecture course was previously offered in the physics department using the same text Optics by Hecht. The addition of the teaching laboratory resulted in the elimination of 18 lecture hours and required the consequent reduction in the course material covered. Part of

the deleted material is covered in the laboratory, and additional topics not covered in the course are added through the laboratory experiments. The lecture material covered is listed in Table I. TABLE I P HYSICS/ECE 411/611 OPTICS FOR SCIENTISTS AND ENGINEERS

Wk 1 2 3 4 5 6 7 7 8 9 10 11 12 12 13 14 15 16

Topic

Text

Properties of waves EM nature of light Dispersion Index of refraction Lenses, stops Mirrors/prisms Fiber optics and sensors Exam 1 Polarization Reflection S/P Superposition of waves Interference Diffraction Exam 2

Lab

Ch 1, 2 Ch 3.1-3.4 Ch 3.5-3.7 Ch 4.1-4.5 Ch 5.1-5.3 Ch 5.4-5.5 Ch 5.6

1 2 3 4 5

Ch 8.1-8.2 Ch 4.6-4.9 Ch 7.1-7.2 Ch 9 Ch 10

6 7 8 9 10 major major major

Present results

Course materials were available to students through the university’s Blackboard CourseInfo 4.0 website. While two exams were scheduled in the fall of 2001 for the lecture material, the majority of students felt that there should be three exams for the amount of material covered. While we originally proposed six experiments designed to be completed in one or two three-hour blocks, in practice we found it easier to break them into the ten separate experiments listed in Table II. TABLE II P HYSICS/ECE 411/611 OPTICS LABORATORIES

Lab 1 2 3 4 5 6 7 8 9 10 Major

Topic Detection of light Absorption Index of refraction, total internal reflection, and critical angle Lenses and simple lens systems Fiber optic numerical aperture Fiber optic light attenuation Single-mode fibers Optical polarization Interference and diffraction Spectrometry Optics project related to academic major

A final optics experiment related to the students academic major (engineering, chemistry, physics, etc.) was added for the last four-week project. This required the students to do background learning on their own, and they presented their results as a PowerPoint® presentation to the entire class during the final week of the course. A number

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Session S4A of excellent topics were introduced to the class in this way that would not normally be covered in an optics course.

IMPLEMENTATION Our optics course was implemented by adapting successful laboratory experiments developed under NSF funding, at the New Jersey Institute of Technology, and through commercially available fiber optics kits from Newport Corporation. This was accomplished surprisingly well, but there were some lessons learned that we wish to share. The principal investigator visited Professor John Frederici at NJIT and toured their teaching laboratory. He graciously provided copies of all the laboratory experiment write-ups that they have in addition to providing access to most of their materials over the Web. The suggestions and ideas from observing the operations first hand were invaluable. For example, four 3x5 foot optical breadboards were originally planned as a cost-saving approach. Based on inputs from NJIT we went the extra mile and obtained 4x8 foot Newport optical tables (see Figure 1). These worked out very well, allowing plenty of space for the laboratory experiments and enough room so that students had their own dedicated space for the major-related experiments. We recommend such a visit prior to writing a proposal for adapting a course, if possible, since a number of our original ideas were revised based on experiences at NJIT. We extend an invitation to anyone who is planning or currently has an optics teaching laboratory to visit us and exchange experiences. After receiving the NSF grant, purchasing the required equipment was the major activity to prepare for the course. Seventy-five separate items were ordered (kits, systems, computers, individual components, etc.), usually in multiples of four. The specifications for each component or system needed to be evaluated to determine if it would work for the proposed experiments. Also, because our budget was very limited, we needed to do cost comparisons between the suppliers for each component. The next major activity was to adapt the write-ups to match the equipment that was obtained and to integrate them into the course syllabus. Often the write-ups required additional modifications during the first course laboratory section in which the experiment was offered. An example of difficulty in meshing the experiments together was the acquisition of HeNe lasers for the Newport Fiber Optics kits. They were optimized for launching light into single-mode fibers, but their beam waists were too small with consequent large beam divergence for doing several of the NJIT experiments, such as the laser telescope, without first expanding the laser beam. We hope to follow the NJIT approach of computer interfaced experiments. This was not possible within the time and budget constraints of our initial course offering. In particular, we plan to automate the experiments for

FIGURE 1 NDSU OPTICS T EACHING LABORATORY

measuring the intensities of diffraction patterns using motorized translation stages and/or CCD cameras. We chose a LabVIEW™ Instruments Starter Kit from National Instruments that includes a high-speed digitizer (oscilloscope card), digital multimeter card, and function generator card installed in Pentium III personal computers in addition to the LabVIEW Full Development System for our data acquisition [8]. This was a cost-saving approach over purchasing individual instruments and also allows us to do computer acquisition. The optical fiber experiments offered important opportunities and challenges. The experience of the students in cleaving their own fibers was deemed invaluable. Launching the fiber into the single mode fibers was very time consuming using the manual alignment apparatus. In order to save time, the laser and holder were aligned prior to the laboratory.

M AJOR-RELATED EXPERIMENTS

Students have a choice of performing one of several major experiments as their final course activity. This experimental effort normally involves pairs of students with common interests. Typically these advanced experiments involve projects in optics, chemistry, image processing, and fiber optics. The major-related experiments were selected by the students and done in groups of two or three. They were also required to write a group research paper on their experiment. Their topics were: • Design and Implementation of a Laser Seismograph • The Fiberoptic Interferometer • Optical Analog Voice Transmission System • Multimode Intensity Sensors • Optical Transmission of Audio Signals • Vibration Measurement Using Laser Interferometry • Specular and Diffuse Reflection Comparisons of Surfaces at IR and Visible Wavelengths 0-7803-7444-4/02/$17.00 © 2002 IEEE November 6 - 9, 2002, Boston, MA 32 nd ASEE/IEEE Frontiers in Education Conference S4A-10

Session S4A •

Emissivity and Infrared Imaging

Students in the fall 2001 offering of the course were not prepared to make the selection of an experiment related to their major. This is being addressed in the 2002 offering by emphasizing it at the beginning of the course and by introducing possible topics throughout the course. Most students expend considerable effort in performing their major-related experiment. It was not uncommon for them to redefine or to redo part of the experiment to either obtain meaningful results or to refine marginal data. The final outcomes of these experiments were presented orally (with PowerPoint) and a written report was also submitted. Some presentations included a live demonstration. All instructors and students were expected to attend all oral presentations, which required some arranged hours on a few days and allowed each student group to respond to questions from the audience. Instructors evaluated the oral presentations based on technical content, oral delivery, visual aids, and relevance. Alternative interpretations by the audience of experimental results created spirited discussions among everyone, sometimes with no definitive conclusions. The live demonstrations were of considerable interest, even when they didn’t demonstrate the sensitivity that might be expected in a scientific setting. Refinement of experimental results is expected to improve in the future as major projects are initiated earlier in the semester. The written reports of the major experiments were due shortly after the oral presentations, and the qualities of these were mixed. Detailed drawings of the various layouts and diagrams, and rewriting some of the interpretations required more time than was available at the very end of the semester. The instructors also learned that the major projects needed careful guidance so that meaningful quantitative data, as well as qualitative interpretations, were obtained.

EVALUATION The new optics laboratory provides a great experience for students. Many of these students see lots of labs dealing with circuits and computers, but this course gives them a chance to exercise their mechanical skills, spatial reasoning, and application of optics theory to very concrete experimental situations. The experiments can be very time consuming. This is probably an inherent part of the learning experience. In some cases the time on task will be reduced as the instructors gain more experience with the course and its laboratories and, hopefully, find more student-friendly components to use in the experiments. The instructors put much more time into the course than would be dictated by its student-credit-hour value, and this will continue in the near term. The administration has granted a reduction in teaching load to facilitate this. The team of four instructors worked well together even though

the workload distribution among them varied. The success of the course would be diminished significantly without the involvement of the four. The students are challenged by the theoretical and experimental rigor of the course. Their background is two years of calculus and differential equations and one year of university physics. In principle they have the appropriate background, but this is probably one of the first times some of the students have had to apply particular results from previous courses to an area that is new to them. One plan for the future to help students in this regard would be to put some review material on the Web. It took some students time to become accustomed to the team approach that was used in the labs. Some reports were written as group efforts. At times the writing fell on one student who would turn the work in without consulting the other one or two students involved. To deal with this situation, questions on the laboratory experiments were included in the examinations in order to assess each student’s understanding of laboratory procedures. Seventeen students completed a survey questionnaire on various aspects of the course. Most students (94%) claimed they went from a novice’s knowledge of the material to qualified knowledge. Many (88%) would prefer more frequent examinations. All students were very active in doing their major projects, but they indicated a preference for an earlier start. The students felt that at the beginning of the course they were not competent in laboratory techniques covered in this course (76%), but, on the other hand, they felt that their theoretical background for the course was good (also 76%). The survey results further indicated that prescribed experiments on light detection, absorption, refraction indices, lenses, fiber optic phenomena, polarization, interference and diffraction were valuable in meeting the course objectives (88%). The surveys also helped to focus instructor effort on certain aspects of particular experiments that needed to be improved. An open house for the new optics laboratory was held near the end of the Fall Semester of 2001 and the campus community was invited. Students in the course have shared by word of mouth their experiences, and the instructors have heard in various contexts on campus a general favorable response that is very heartening.

CONCLUSIONS AND FUTURE PLANS The Optics for Scientists and Engineers course has been very successful. We plan to offer it annually and possibly every semester if the anticipated interest is achieved. Because of the hands-on experience we are limited to 24 students per semester. We plan to incorporate the optics teaching laboratory into all the courses for our Optical Engineering and Optical Science and Engineering options. Immediate applications will be to the existing Optical Electronics (second harmonic and parametric generation) and Optical

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Session S4A Signal Transmission (fiber optics) courses. Anticipated future courses include: (i) a computer-equipment interface course based on LabVIEW (using motorized translation stages, optical detectors and spectrometers) in the teaching laboratory and (ii) a laser course.

ACKNOWLEDGMENTS We would like to acknowledge the support of our department chairs and other administrators at NDSU along with Dr. Orlando R. Baiocchi (former ECE Department Chair) who was instrumental in initiating this project and Dr. Khan Iftekharuddin (former NDSU faculty member) who was an original co-PI of this project.

REFERENCES [1] Barat, R., J. Federici, A. Johnson, H. Gebel, and T. Chang, “Optical Science and Engineering Curriculum at NJIT,” Journal of Engineering Education, 1998 Supplement, pp. 575-582. [2] New Jersey Institute of Technology Optical Science and Engineering (OPSE) program, http://www.njit.edu/Directory/Centers/OPSE/OPSE301/opse301.htm . [3] Hecht, E., Optics, San Francisco: Addison Wesley, Fourth Edition, 2002. [4] National Research Council, Committee on Optical Science and Engineering, Harnessing Light, Optical Science and Engineering for the 21st Century, Washington, DC: National Academy Press, 1998. [5] Johnson, A. M. and C. B. Hitz, “Career Opportunities in Optics,” Physics Today, May 2000, pp 25-28. [6] Keiser, G., Optical Fiber Communications, New York: McGraw-Hill, Third Edition, 2000, pp. 533-568. [7] Newport Corporation Web site: http://www.newport.com. [8] National Instruments Web site: http://www.ni.com.

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