Spring 2020

Spring 2020: Optics Lab (PHYC 302L, 476L, & 477L)

Instructor: Victor Acosta, victormarcelacosta@gmail.com

Office: CHTM, Rm 115A (please make an appointment)

Teaching Assistants: Subhashree Seth, sseth@unm.edu & Biswesar Patra, bpatra@unm.edu

Class meets:

476L/302L-001: Mondays 1:00 - 4:50pm;

477L/302L-002: Fridays 9:00a - 12:50pm.

Location:

First 30 minutes if lecture or mini-talk is scheduled: PAIS 1140 (Mondays), PAIS 1160 (Fridays).

Remainder of class: PAIS 1417 (lab)

Textbook: None.

Final exam: Pairs of students deliver oral presentations (30 min). Notify the instructor ASAP if you have a conflict.

476L/302L-001: Monday, May 11, 1-5p, PAIS 1140;

477L/302L-002: Friday, May 15, 9a-1p in PAIS 1160.

Class schedules: These spreadsheets contain all deadlines. They may change, so please check frequently.

Mondays: 476L/302L-001.

Fridays: 477L/302L-002.

Syllabus: This webpage is your syllabus.

Slides: Intro slides here. Photon statistics talk here.

Overview: Experimental Optics Lab is organized around modules that are expected to last about 4 weeks. The modules are more complicated than lower-division undergraduate labs. You will find less specific instruction; independent problem-solving is expected. The goal is to provide an environment in which to develop laboratory skills.

The course is broken into 3 modules, each lasting 4-5 weeks. Students should work in teams of 2 (or, if necessary, 1). Team members will be rotated at the conclusion of each module. Students are encouraged to switch partners after every module. Students are required to complete the following, in order, before May 11 (finals week):

-2 standard modules from the list below

-One final project module.

Standard Modules:

1) Wavemeter. Instructions. This experiment is shared with Senior Lab.

2) Doppler Velocimetry. Instructions. This experiment is shared with Senior Lab.

3) Saturated Absorption spectroscopy. Instructions. This experiment is shared with Senior Lab.

4) Mode-locked laser. Instructions.

5) Nonlinear Optics. Instructions. For intro to NLO, see text by Boyd. link1. link2. **not yet available due to move

6) Diffraction of Single Photons. Instructions. Photon number calculation. Coherence length.

7) Fourier Optics. Instructions.

8) Fiber Optics. Instructions. 302L only Corrigendum.

9) Polarization. Instructions. 302L only **not yet available due to move

302L students: You must choose either 8) Fiber Optics or 9) Polarization as your 1st module. After that, all experiments are available.

476/477L students: Do not choose the Polarization or Fiber experiments as a standard module. All others available.

Final Project Module: Students will choose any of the above experiments or any of the other experiments available in the optics labs or purchase/build custom hardware on P&A budget (provided it is not too expensive) :

1) Develop and test their own hypothesis that is different from the standard lab module. Meet with instructor in early March to discuss and submit a 1-page proposal due before spring break. Proposals are pass/fail, but the instructor will provide feedback. The quality of your scientific question and experimental plan are part of your final project grade.

2) Automate the experiment and acquire data using LabView (ideally).

3) Present findings in 30 min oral presentation (in place of written final exam).

Grading: Students will be graded on:

-participation (including electronic lab notebook and mini-talks), 15%.

-standard module writeups, 25% x 2.

-final project, including oral presentation, 35%.

Each module will be graded on the quality of the work and the clarity and professionalism of the writeup/oral presentation. Late assignments will be marked down one full letter grade for each week late. The instructor and TAs will often be working directly with the student teams and will have plenty of opportunity to assess your progress. Be sure to engage them in discussion and ask plenty of questions. Students must attend each lab session unless explicitly excused by the instructor. Participation is important and unexcused absences will affect the first component of grading.

Lab Notebook: At least one student from each group is expected to bring a laptop to each class. On every module, each team will be responsible for maintaining a detailed electronic notebook file. Thus in total, each student will have 3 different notebook files and each file will have 2 (or, if necessary, 1) authors. We will use Google Docs to record all information; this will make writeups easier and allow for easy collaboration amongst teams. Relevant information should be recorded as the experiment progresses. A useful description (if somewhat outdated) of the lab notebook procedure can be found here. The instructor and TAs will periodically look through the lab notebooks unannounced. You will be graded on completeness and clarity of information. This is a case where style is less important and we encourage you to use shorthand, photos, screenshots, etc. to make the note-taking process less time consuming. Please create and share your Google doc with victormarcelacosta@gmail.com, sseth@unm.edu, and bpatra@unm.edu at the beginning of every module.

Writeups: Developing technical writing skills is an important component of this course. An accomplished scientist must be adept at properly explaining and documenting his/her work following established conventions. There are many brilliant physicists who have been hampered in their professional careers because of an inability to do this well.

For the standard modules, each student on the team is responsible for producing their own report no later than 2 weeks after the completion of the module. The writeup should follow the format of a formal technical document that you would see in a physics journal such as Physical Review Letters. There should be an abstract that concisely summarizes what you have done. An Introduction orients the reader to the work with background material. There should be a section that clearly describes the experiment with diagrams and details. This is followed by sections for Results (graphs and/or tables are almost mandatory), Analysis/Discussion, and a short Conclusion. References are listed last.

The Results section is among the most important sections. It is a good idea to discuss with the instructor and TAs what your plots might look like before you acquire data. This will allow you to acquire data in a comprehensive way so that, when you've rendered the final figures, the reader can easily visualize your results. Analysis should follow rigorous statistical methods for parameter and uncertainty estimation.

Use a template from a research journal of your choice (eg. APS, OSA). OSA templates can be found here. Search online or simply look in the hallways of our physics building for plenty of examples. There is no page requirement, but be sure to write clearly and concisely. The 2-week deadline is in place for two reasons: i) it's best to work on the report while details are fresh in your mind and ii) you should begin organizing your ideas and thoughts for the writeup while the experiment is in progress.

To create the writeups, students may use latex, Google docs, Word, or any other standard processor. In my research, I personally prefer using a cloud-sharing processor such as google docs or Overleaf (for latex).

Mini-talks: Pairs of students will be assigned a topic and will deliver a 15-20 minute talk on this topic at the beginning of class. Each student will give one talk during the semester. These are not graded, but attendance is included in your participation grade, so ask questions and do your best when it is your turn. The instructor will give the first mini-talk and give out pointers.

Final oral presentation: Each pair of students will deliver an oral presentation during our final exam timeslot. Presentations will cover the work done on the final projects. They should be 30 minutes in length, and there will be an additional 10 min for Q/A. The format of the talk should follow that of a standard research talk at, for example, APS March Meeting.

MODIFICATIONS in response to COVID19 pandemic:

-All students will receive at least a B+ in the course (or CR if you prefer CR/NC) if they submitted Module 1 on time or with pre-approved exception.

-The remaining mini-talks have been canceled. If you would like to schedule a time to practice your public-speaking skills prior to your final presentation, contact Victor directly.

-Module 2 is now optional. The better of your Module 1 and Module 2 grades will be applied to both module grades. Due date is May 1.

-Three choices for final projects:

1. At-home experiment + oral presentation (take measurements yourself, option to work remotely with partner)

2. At-home experiment + oral presentation (do not take measurements yourself, but work remotely with partner)

3. Written assignment with partner. Write new lab manuals for 2 of the standard modules. Grading rubric includes:

a. how different the new manual is to old manual

b. clarity of writing

c. use of visual aids

d. compatibility of manual with course learning objectives (independent problem solving, rigorous data analysis)

Written final-project assignments are due Friday May 15. Oral final-project presentations may be completed either May 11 (1-5p) or May 15 (9a-1p).