# Physical Optics (spring 2012)

Instructor(s):
Name email homepage office phone
Andy Rundquistarundquist@hamline.eduhttp://www.hamline.edu/~arundquistRobbins Science 124651-252-1778

See month by month calendar here

# Text

Physics of Light and Optics by Justin Peatross and Michael Ware

layersolve mma for chapter 4

linear curve fitting in Mathematica

error propagation

# Office Hours

See empty space on my calendar between 8 and 4

schedule an appointment with me here

standard assignments (instructor password required)

standard assignments in table form for cutting and pasting into daily outline

recent standard submissions (instructor password required)

randomize students (instructor password required)

form groups

# Backchannels

Outside of class we'll use GroupMe (a texting version of a listserv) for quick announcements and questions, my summary and questions page for questions to be dealt with in class.

# Assessment

## Standards

### Lab standards

1. I can propagate errors.
2. I can fit data to a model.
3. I can write an organized lab report.
• Note that the formal lab report is not due for every lab. You can choose which labs you'd like to write a formal report for.
• If you don't write a formal report, you need to give a screencast carefully explaining all aspects of the lab.
4. I can be a helpful team member when collecting data
• Note that your peers will determine this. Each will debate the rubric score for each member at the end of data collection and give an in-person or screencast report to me of the scores.
• You can change the scores after analysis if you realize something went wrong and you didn't realize it.
5. I can measure the speed of light.
6. I can measure the index of refraction from reflection data.
7. I can measure the wavelength spacing of laser lines with a Fabry-Perot interferometer.
8. I can experimentally determine the parameters of an unknown waveplate.
9. I can measure the circular birefringence of Karo syrup.
10. I can measure the pressure dependence of the index of refraction of air.
11. I can measure the wavelength of light with a ruler.

### Chapter 1 Electromagnetic Phenomena

1. I can explain the foundations of, usefulness of, and ramifications of the four Maxwell Equations, both from a differential and integral point of view and I can derive the wave equation for light from Maxwell's equations.

### Chapter 2 Plane Waves and Refractive Index

1. I can explain the plane wave solutions of the wave equation.
• Note that P1.9 is good for this.
• note that P1.2 is good for this.
2. I can derive the form of the complex index of refraction and the Lorentz Model for index of refraction.
3. I can calculate and plot the index of refraction for an interesting Lorentz Model material, including conductors.
4. I can discuss the foundations of, usefulness of, and ramifications of the Poynting theorem.

### Chapter 3 Reflection and Refraction

1. I can prove equations 3.4 through 3.7 and I can derive the equations 3.8, 3.9, 3.13, and 3.14.
2. I can plot the reflectance and transmission for s and p polarized light
• You should be able to redo figures 3.3 and 3.4
3. I can discuss the foundations of, usefulness of, and ramifications of the evanescent field in total internal reflection.

### Chapter 4 Multiple Parallel Interfaces

1. I can explain the Mathematica approach to solving for the fields involved.
2. I can calculate, using Mathematica, the transmission and reflection for an interesting multiple parallel interface problem.

### Chapter 6 Polarization of Light

1. I can explain the mathematical representation of various forms of polarized light and discuss the foundations of, usefulness of, and ramifications of the Jones vectors and matrices.
2. I can calculate the polarization state of light after passing through an interesting system using Jones vectors and matrices.

### Chapter 9 Light as Rays

1. I can discuss the foundations of, usefulness of, and ramifications of the Eikonal Equation and show the connection between the Eikonal equation and Fermat's principle.
2. I can discuss the foundations of, usefulness of, and ramifications of the ABCD matrices.
3. I can derive the ABCD matrices for a curved interface.
• reflection or transmission
• concave or convex
4. I can use the ABCD approach to prove the lens equation
5. I can model an interesting stable laser cavity.

### Chapter 10 Diffraction

1. I can explain the connections among equations 10.1, 10.13, and 10.19.
• Huygen
• Fresnel
• Fraunhofer
2. I can make a plot of the intensity pattern for an interesting aperture at an arbitrary distance behind it.

### Chapter 11 Diffraction Applications

1. I can derive and calculate the intensity diffraction pattern for a periodic aperture.
2. I can do an interesting resolution problem.

## Rubric

### 4 level scale

Much of this was inspired by/copied from Frank Noschese's work on SBG

Note: Not assessed: 0

1. Doesn't meet expectations: 1
• I need lots of help from my instructor (one-on-one).
• I have low confidence on how to do the skills and need more instruction.
• I need my textbook/notes at all times.
• I do not understand the concept/skills.
• I cannot correctly identify concepts and/or define vocabulary.
• I cannot make connections among ideas or extend the information.
• My responses lack detail necessary to demonstrate basic understanding.
• Cannot articulate most of the main ideas involved in the standard
2. Approaches expectations: 2
• I have a general understanding of the content/skills, but I'm also confused about some important parts.
• I need some help from my instructor (one-on-one or small group) to do the skills correctly
• I do not feel confident enough to do the skills on my own
• I need my textbook/notes most of the time.
• I can correctly identify concepts and/or define vocabulary; however I cannot make connections among ideas and/or independently extend my own learning.
• My responses demonstrate basic understanding of some main ideas, but significant information is missing.
3. Meets expectations: 3
• I understand the important things about the content/skills.
• I have confidence on how to do the skills on my own most of the time, but I need to continue practicing some parts that still give me problems.
• I need my handouts and notes once in a while.
• I am proficient at describing terms and independently connecting them with concepts.
• I understand not just the "what," but can correctly explain the "how" and "why" of scientific processes.
• My responses demonstrate in-depth understanding of main ideas.
4. Exceeds expectations: 4
• I understand the content/skills completely and can explain them in detail.
• I can explain/teach the skills to another student.
• I have high confidence on how to do the skills.
• I can have a conversation about the skills.
• I can independently demonstrate extensions of my knowledge.
• I can create analogies and/or find connections between different areas within the sciences or between science and other areas of study.
• My responses demonstrate in-depth understanding of main ideas and of related details.

# Policies

We will be using a very different assessment approach this semester. It is called "Standards-Based Grading" and it addresses the following issues I've had with students in the past:

• Students cram for an exam but sometimes don't retain the information
• Students can sometimes be more focussed on points than learning
• If a student doesn't "get it" at the time of homework being due or the exam, they lose the points, even if they clearly learn it by the final.

The basic idea is that there are certain things the department thinks you should learn in this class. Those are what I'll call the "standards." Typically every chapter we cover will have around 3 standards and there will also be a few holistic standards as well.

For each standard you will be assessed many times. An assessment might cover 2 or 3 standards but you can also come up with your own ways to assess your learning. Every time a standard is assessed, the score for that standard is updated in the gradebook. The score might go up and it might go down. You can reassess any standard often, at least within reason.

Here are some of the types of assessments we'll use:

• Pencasts
• you can borrow my Livescribe pens and paper pads at any time to do a pencast on a problem that addresses one or more standard. You then return the pen to turn it in.
• Screencasts
• you can use Jing to record your screen.
• you can do this for a Mathematica document
• You walk me through your calculation
• you can use pre-approved "cut and paste" materials/functions. Everything else has to be typed in real time
• You can do this for a scanned document in place of a pencast
• Exams
• There are a few times in the semester where I've scheduled breaks for review and assessment. Here we can do oral testing in class for particular standards.
• Prior to each day you will be told the standard you have to perform. You can write one page of notes to bring to the assessment.
• In class, you will be up from for a maximum time of 5 minutes.
• For the first minute, I will silently review your whiteboard and frame my questions
• You will spend the next 3 minutes answering my questions.
• As a class, we will spend 1 minute determining your score.
• Office visits
• If you schedule it in advance (including mentioning the standard you want assessed), you can come to my office to work a problem in front of me
• Online office hours
• We can use my online office hours in the same way (again, with some advanced notice)

95% of your grade depends on how you do on the standards assessment. I will simply add up your points and divide by the total. Some standards are on a 4-pt scale (doesn't meet, approaches, meets, exceeds the expectations) and some are on a two point scale (yes or no).

We will also have a final in this class. On the final you will make a mind-map of the standards and discuss several of the important connections. This will represent the final 5% of your grade.

## Two week rule

Once a standard has become active (meaning we've worked on it in class), you have two weeks to turn in your first assessment for it. If you don't, you must take a zero for that standard for the course.

This particular policy came about to address the chronic procrastination in a previous course that used a similar assessment technique. When students wait until the end of the term to begin to turn in assessments, there are a few problems:

1. The student doesn't benefit from feedback as well since the timeline is shortened.
2. The student isn't ready for newer material because he or she hasn't put the time in to learn the old material.

The benefit to the whole class will be that I will have seen at least one assessment from everyone within two weeks and I can do some triage on difficult concepts early on. During every class I will announce which standards have expired and I'll discuss the common problems I've seen in the screencasts. This should help everyone much more than in previous classes.

## Brevity

Being able to show your understanding of material efficiently a sign of deeper understanding. It shows that you know the priority of the important concepts, as you don't spend too much time on less important ones. You will not receive a 4 (see scale below) for a technically correct assessment, even one whose content is "brag-worthy," if it is deemed to be too long. A good rule of thumb for the duration of a typical assessment is ten minutes.

 letter grade: rounded score >= A A- B+ B B- C+ C C- D+ D D- F 94 90 87 84 80 77 74 70 67 64 60 0

## Lab

how to use nonlinearmodelfit and errorbars

Here is the format of a lab report. Note that you don't have to produce one of these for every lab. Some can just be screencasts walking me through the set up and analysis.

Introduction
A basic introduction about what the lab is intended to study
Theory
All the physics derivations and explanations should be here
Set-up/procedure
A description for how the experimental equipment is set-up and used
Data
A representative sample of your data should be here (typically either a table or a graph)
Analysis
Here you should analyze the data to determine the result you're looking for. This is also where all error analysis should be performed. Also, any curve fits should be explained here (they graphs of the curve fits can be in the data section).
Conclusion
Here you should compare your results with other similar experiments and comment on the results of your error analysis. If you say the cause of error was "human error" you will fail this course.

Students should use lab notebooks to takes notes and collect data but not for the final reports which should be typed.

## Final (5%)

The final will be cumulative of all material covered in the course. My philosophy is that everyone who passes the course should still be able to pass the final six months after the class ends. No calculator is required for the final as the questions will all be short-answer conceptual questions.

## Participation

You can use my summary page to submit a summary and questions about the material: http://aca-fac.hamline.edu/~arundquist/php/summary/index3.php. These questions will be the bulk of the material covered in class.

here's how to use that page

# Daily in class routine

We will devote the first 5 minutes to both student questions and developing a class-wide mind map.

We'll use the last five minutes to make suggestions for further screencast resources.

# Laboratory safety

Please exercise courtesy and common sense judgment when working in the physics laboratory:

• Do not leave books, backpacks, and jackets on the floor when in the lab because we do not want anyone tripping and hurting themselves.
• Do not bring food and drink into the lab when there is any danger of damaging electrical or computer equipment.
• Do not stand near others when using sharp objects (razor blades or scissors). Whenever possible, move or point the cutting blade away from your body.
• Do not look directly at a laser. Maintain a constant light level over the optics table and do not bend so that your eyes are at optical bench level (remember that there are others in the room playing with other lasers at all times and we do not want accidental entry of laser light into your eyes).
• Do not energize electronics circuits without first checking with the instructor. Be especially cautious when working with voltages greater than 50 volts.
• Do not leave plugs to electrical equipment partially exposed and available for accidental connection.
• Never play around with open line voltages (120 V or 240 V AC outlets) because they could kill you.
• Never bring food or drink into the lab when working with radioactive materials.
• Always handle equipment with care. Equipment will occasionally break due to normal usage. Do what you can to help us lengthen the life of our equipment. If you think a piece of equipment is damaged, then please let the instructor know as soon as possible. We want to maintain all of our equipment in good working order.

If you are in doubt about any procedure, or if it may seem unsafe to you, then do not continue. Ask your instructor for help.

Robbins Science Physics Laboratory (Special Concerns)

• RS 8 - General Physics Lab (Electrical Equipment & Computers)
• RS 106 - Physics for Poets Lab (Electrical Equipment)
• RS 115, 123 - Modern Physics Lab (Electrical Equipment, High Voltage, Radiation & Computers)
• RS 119 - Optics Lab (Lasers)
• RS 132 - Electronics Lab (Electrical Equipment)
Dates: