“The important thing in science is not so much to obtain new facts as to discover new ways of thinking about them.” - Sir William Bragg

## Course Meeting Times

Lectures: 2 sessions / week, 1.5 hours / session

Labs: 1 session / week, 3 hours / session

## Course Overview

6.161 offers an introduction to laboratory optics, optical principles, and optical devices and systems. This course covers a wide range of topics, including: polarization properties of light, reflection and refraction, coherence and interference, Fraunhofer and Fresnel diffraction, holography, imaging and transforming properties of lenses, spatial filtering, two-lens coherent optical processor, optical properties of materials, lasers, electro-optic, acousto-optic and liquid-crystal light modulators, optical detectors, optical waveguides and fiber-optic communication systems.

Most optical systems involve the use of many of the principles and components we will study. The goal is to help the student develop a thorough understanding of the underlying physical principles of modern optical devices and systems through hands-on learning. Lectures are supplemented with weekly laboratory exercises, problem sets and a final laboratory project of the student’s choosing. There are 12 design points associated with this subject. Students may use this subject to find an advanced undergraduate project.

There are two lectures and one laboratory period each week for the first eight weeks. During the first several weeks, the lectures will review and develop fundamental principles and concepts in classical optics, and optical and quantum electronics. The remaining lectures address contemporary topics in modern optics.

Since this is a laboratory course, the intent is not to dwell on detailed theoretical treatments of the topics, but to provide a sufficient background for the student to grasp the principles and confirm the associated phenomena in the laboratory. For more theoretical treatments the student is encouraged to enroll in other optics subjects that are specifically designed for this purpose (e.g., 6.630, 6.631, 6.634, and 6.637).

## Prerequisites

The prerequisite is 6.003. Exceptions can be made by the Lecturer.

## Course Content

### Laboratory Exercises

There are seven short laboratory exercises concerned with the measurement and observation of basic optical and quantum phenomena. Each laboratory exercise consists of pre-lab exercises (to be completed before entering the lab) and several experiments dealing with the same theme, designed to complement the lecture material. Each laboratory exercise will be set up by the course staff for one week only, and you must complete each laboratory exercise sometime during the week that it is set up.

Some of the laboratory exercises require a considerable amount of setup time, and once they have been taken apart, they will not be set up again. Laboratory exercise reports must be turned in to the Teaching Assistant (TA) one week after the exercise was scheduled. In the event the report is due on a day when the Institute is closed, the report should be turned in to the TA by 5:00 pm on the first day that classes resume whether or not the Laboratory is open on that day. This may be a day when 6.161 does not meet.

Late homework should be placed in the bin outside the professor’s office or handed directly to the TA. All laboratory write-ups (along with pre-lab exercises) **must** be done in a carbonless-copy lab notebook. Currently, we will only accept lab write-ups using the Hayden McNeil Physical Sciences Student Lab Notebook with Spiral Binding. There is also a spiral-bound Chemical Sciences version of this notebook, which is acceptable. Students must turn in the yellow copies and keep the blue copies for themselves and for reference. Blue copies are **never** to be removed from the lab notebook. Plots, tables and graphs must be pasted onto both the blue and yellow copy. More information as to laboratory write-up specifics is available in the
labs section.

### Homework Problems

The homework problems are designed to encourage outside reading, and to strengthen your grasp of the fundamentals. One homework problem set will be handed out each week and will be due one week later. Problem sets will not be accepted after the solutions are handed out. Points will be deducted for late problem sets.

### Quizzes

There will be two quizzes during the term. The quizzes will be given during the regular 1.5 hour class. These quizzes will cover broad ideas, as presented in lecture, lab, and homework. They will test your understanding of the fundamentals and their applications. These quizzes will be open class notes (Prof. Warde’s course notes). You should not stress over these quizzes. If you have done the reading, attended lecture, completed the homework, and worked the labs, you should have no problem with the quizzes. The quizzes will consist of short questions intended to test your knowledge of basic optical principles and laboratory optics. The quizzes will count for approximately 20% of your grade (10% each). These quizzes will enable the teaching staff to diagnose both our teaching and your comprehension. Quizzes, like homework may be a determining factor if your grade is borderline.

### Final Project

To make all the Final Projects roughly equal in difficulty and time requirement, we will provide you with several possible Final Projects (which will still allow for, and require, innovation). Additionally, we will allow students to start on the Final Project as soon as they want… hopefully reducing end-of-the-term stress. We will provide the necessary lab equipment and all the technical help we can to ensure that your experience is both educational and rewarding. Of course, if you still want to find your own project, or have a hankering to do something different, just tell us, and we will try to accommodate you (in such a case, we would encourage you to look around MIT for groups that may have projects that interest you). Many final projects found outside of class turn into RAships and M.Eng. work.

The written report for the final project should be on the order of 15 to 30 pages in length (please, no longer… you should be able to condense any relevant prose into that space). Additional information is available in the projects section.

## General Policies

To make laboratory exercises flow smoothly, please arrive on time for your assigned lab sessions. Additionally, please come prepared: this means that you will have:

- read the lab material before arriving,
- completed the pre-lab, and
- brought your questions with you.

As part of the pre-lab, you must find and review the equations necessary to complete the lab before you begin. In order to ensure that you will have all the data you need for your write-ups, you will be required to take notes in a laboratory notebook (Hayden McNeil Physical Sciences Spiral Bound Student Lab Notebook). These notebooks may be checked at any time by the TA or professor to make sure they contain all necessary information. A well-kept notebook will help ensure that you not fail to gather all the necessary data for your write-up (as you may not be able to come back and retrieve the data before the apparatus for a given laboratory exercise is dismantled). Additionally, short oral quizzes may be given in lab to test your comprehension of the current laboratory material - these quizzes or notebook checks will count toward your laboratory grade (between 5% and 10% depending on difficulty).

### Grading

The laboratory exercises are an integral part of 6.161, constitute the majority of your learning, and thus the final grade. Each homework problem set makes up a small, but non-negligible portion of the final grade. The two quizzes are obviously very important since they represent 20% of the grade. Your performance on the Final Project is also a very important portion of our evaluation of your overall performance. The approximate percentage values are as follows:

ACTIVITIES | PERCENTAGES |
---|---|

Labs (Active participation in lab, performance on pre-lab, and good laboratory notes will form a significant portion of this grade) | 40% |

Homework | 20% |

In-class Quizzes and In-class Participation | 20% |

Final Project | 20% |

We will take into account participation in-class and in-lab as well as attendance when deciding borderline final grades.

Please note: To earn a passing grade (A,B,C) in this subject, you must complete and write up all seven of the Laboratory Exercises in the prescribed time period. Thus, at the end of the term no incompletes will be given due to incomplete final projects!

Also, since most students do well on both the labs and the Final Project, performance on both the problems sets and quizzes become an extremely important factor in determining the final grades.

### Grading Breakdown

All homework problem sets account for the same number of points (re-normalized at the end of the term). How you got to your answer is very important. Show your work! The grader will deduct points for answers which lack justification. The worth of each Laboratory Exercise is based on the length and difficulty of the lab (e.g. Lab 3 counts for more than Lab. 1). For all labs, write your answers in your lab notebooks. Be sure to include derivations, solutions, graphs, diagrams, data, and physical explanation when answering the lab questions. Be sure to include copies of any computer print-outs on both the normal sheet and the second carbonless copy sheet.

**Note from the TA**: Please do not become discouraged if your score on the first lab seems low. Lab 1, while it does count as part of the final grade, should be viewed as a steppingstone into the course. Just do the best you can on this Lab. Assume nothing, and be very thorough! Do not assume that the grader knows how you arrived at your answers. Assume the grader has never taken this class, and thus needs a full and detailed explanation. While you may have the correct answer, how you got there is more important! You will not receive credit for answers without explanation.) The TA will only grade your lab report if you showed up to lab and actively participated in the lab experiments.

### Neatness and Clarity

To ensure that you get the maximum number of points on each Lab and homework assignment, make sure to be neat! The TA or grader will not grade messy work. Additionally, messy work will delay turnaround on both problem sets and homework. Questions on both problems sets and labs must be answered clearly and succinctly. The TA will be looking for demonstrated understanding. It is preferred that you explain in words when possible; this will ensure that you get the maximum number of points for your effort. However, do not neglect mathematical rigor. When math is needed, it must have the proper units and be clearly written. The TA and a grader grade all labs and homework; the more clear and succinct your answers, the better. However, do not compromise important details. The grader will not accept numerical answers without their derivation. Likewise, the grader will not accept written answers, without appropriate reasoning.

### Labeling and Formatting

Whenever a problem asks for a graph, the student must create computer-generated graphs. All graphs must be labeled and titled - a copy of the graph must exist both on the blue and yellow carbonless-copy sheets of your lab notebook. Use callouts to point out important regions of your graphs. Any written answers exceeding one page must be typed. It is suggested that you format all your answers using LaTeX or a comparable typesetting package. If you wish to use one of your labs for the Writing Requirement, notify the TA beforehand.

Label your answers clearly; the grader will not search extensively for an answer. Circle your answers, and underline key portions of your work which directly aid in the creation of the answer. Points may not be given back if an answer is skipped in the grading process because the answer was difficult to find.

### MATLAB®, Mathematica®, LabView and Maple®

When computer-based problems are presented, please use MATLAB®, Mathematica®, LabView or Maple® to do your work. If you feel much more comfortable with other math packages, that is okay, but please put the code in your public directory along with instructions on its execution. Please include any code and graphs you use in your solutions. Often, unless stated, graphical solutions may be used, especially if they show that you really understand the material. To use MATLAB®, Mathematica® or Maple® on the MIT server, type: add MATLAB®, add math, and add maple® at the server prompt. These software packages can also be found on the lab machines.

### Late-Work Policy

Having been an undergraduate once, your TA knows that many of you have obligations which inhibit your ability (on rare occasions) to turn in work on time. If such an emergency arises, notify the TA before the homework is due (if possible). In order to be fair to your classmates, we must still penalize late work (unless the tardiness was due to medical or similarly urgent reasons). Additionally, an incomplete problem set will not be accepted. We expect you to make an effort on **all** parts of **all** problems. This gives us the chance to see where you are having problems, if any. If you need additional time, ask for it. You will always receive more points for a completed late problem set than an on-time incomplete one (assuming you turn it in before solutions are handed out). If tardiness becomes a chronic problem, it will significantly degrade our final evaluation of your performance.

### Collaboration

Collaboration is encouraged. Talking with peers about problems helps everyone (“To teach is to learn twice.” - Joseph Joubert). However, blatant copying and other forms of cheating will not be tolerated. Always acknowledge your collaborators. In no way can this hurt your grade (in fact, it may help). We care that you learn the material - if you learn it best from a friend, that’s fine.

Questions regarding problem sets and labs should be addressed to the class collaboration webpage. So collaboration (online) must be done through the moderated collaboration Web page. That way everyone has access to the same resources; and if you have a problem or question, someone may be able to help you - including the TA. There you can get help from the Lab staff, as well as your peers.

### Office Hours

Office Hours will be conducted weekly, by appointment. Office hours will address questions from the laboratory exercises, quizzes, and problem sets. Office hours may also include hands-on demonstrations of applied concepts. While office hours are not mandatory, they may cover concepts and material that may show up on quizzes, homework and labs. Students are expected to ask questions and come to office hours prepared. Questions and concerns addressed on the class electronic mailing list, as well as the class collaboration page may be addressed in office hours.