Revision as of 02:21, 8 October 2015

Course Information

Professor: Dr. Charles Durfee

Office: Meyer Hall 330

Meeting Times:

class: M W 11:00-11:50 AM Berthoud Hall 205

lab: Th 9-11:50, Meyer Hall 263

Announcements

7 October 2015: The revised lab is posted - you should finish these this week. Remember the Sagnac interferometer is extra credit. Also, there are only two Fabry-Perot interferometers and you don't need to interfere with your other setup to use either one. So be sure to do that one when it's available.

5 October 2015: Posted slides for today and wednesday. They are bundled in the EMWaves and interference file.

2 October 2015: HW 4 is re-posted with 3 additional interference problems. This homework will be due Friday of next week. I will be out of town tuesday afternoon until thursday morning for a grant review meeting in DC. Mike Greco will be teaching in my place on Wednesday.

30 September 2015: Class notes and this week's lab are posted below.

29 September 2015: I posted the neon spectral data. As I posted it, I realized the file format will need to be converted to a tab delimited or .csv so other programs like Excel or mathematica can read it. Could someone read the .prospec file into the spectrometer software and do the conversion? When you do, email it to me and I'll post it.

Also notice the file that is there that describes the different transitions that participate in the neon inversion and the decay out of the laser termination state. This will help you interpret the changes in the emission spectrum from not lasing to lasing.

28 September 2015: As discussed in class, homework 4 will be due Oct 7. I will re-post it with some additional questions to account for the second week. In the meantime, I've posted a pdf of the current homework that has the figure for problem 1.

I have the solutions for HW1 and 2 printed out. They are available in my office if you'd like to look or make a copy.

27 September 2015: Homework 4 is posted.

22 September 2015: Homework 3 hints and tips: On the last problem, you need a value for the saturation fluence. Use 0.85 J/cm2, which is the saturation fluence for Ti:sapphire. I put this in an updated copy of the homework assignment.

21 September 2015: Homework 3 hints and tips: Problem 3: For both parts a and b, the central frequency is 10^14 Hz. I had it listed just for part b. If you need a refractive index for this problem, you can take n = 1. One way to approach this problem is to first find the Einstein coefficient B21 first.

Problem 4: For this, it is helpful to work with equations in chapter 2 to get a connection between the spontaneous emission rate and the cross-section that is independent of the dipole moment.

14 September 2015: Homework 3 is posted. This is due in 1 1/2 weeks, but of course getting started earlier is better.

4 September 2015: Homework 2 is posted. The file is in Mathematica format, since most of the problems can be done in that program.

2 September 2015: Lecture notes for Wednesday are posted: see below. Later I will rearrange the files so they reflect what we actually get to in each class.

31 August 2015: Lecture notes for Monday are posted: see below. I re-posted the slides just after class, to fix a couple of typos and to add a couple of figures. We got up through slide 17 today, but we'll review a bit in the beginning of class on Wednesday. Read through the slides, work through the missing steps, and bring your questions to class on Wednesday.

26 August 2015: Lecture notes are updated, and the lab for Thursday is posted below.

If you have a Windows laptop, please bring it to the lab.

You can load the software for the power meter using this website:

PM100 software

This should work for any version of Windows.

The camera software is at this site:

Camera software

This only works on Windows 7.

For later versions of Windows (at least 8), this driver should work. [1]

23 August 2015: Welcome to Laser Physics!

Office hours

Times: M12:30-3:00, W1:00-3:30

Let me know if you cannot make any of these office hours. I have monthly meetings on wednesdays, so the wednesday hours will occasionally shift to 1-4.

Look for me either in my office or in the advanced lab on the second floor.

Course Material

Syllabus and Reading List

Main text: O. Svelto, Principles of Lasers, 5th edition. It is available for purchase at the bookstore. There is also online access to the book from a campus/VPN connection:

http://www.springerlink.com/content/n72670/#section=672851&page=1

These downloads require Adobe Acrobat Reader Course syllabus for 2015

Homework Assignments and Midterm:

Grading policy:

Turn in homework on time for full credit. At the time we give homeworks back to you, solutions will be available in printed form in a binder that I'll keep, but you can make a copy.

These downloads require Adobe Acrobat Reader Homework 1 due by 5pm 2 Sept. Homework 2 due by 5pm 9 Sept. Homework 3 due by 5pm 23 Sept. Homework 4 due by 5pm 9 Oct. New deadline, 3 additional problems on interferometry. Be sure to do the interferometry problems before Thursday's lab. Homework 4 pdf version

Lab exercises:

This section is for 2015

These downloads require Adobe Acrobat Reader Lab 1: optical alignment skills Lab 2: HeNe gain and lasing Lab 2: some background reading about HeNe lasers. Lab 2: zip file containing .png picture of Neon spectrum and a spectrometer data file that needs to be converted to .csv or tab delimited. Lab 3: interferometry. This version has another couple of exercises on Fabry-Perot and Fizeau interferometers.

Below here are the write-ups for 2013. There will be edits and changes for 2015.

These downloads require Adobe Acrobat Reader Lab 4: HeNe resonator modes Lab 5: HeNe resonator modes 2

Final project

These downloads require Adobe Acrobat Reader

Lecture Notes

While these notes are primarily to help me give my lectures, I'm posting them to help you fill in things you may have missed in class or to show the details of calculations we don't have time to work through. If you have any constructive input on how to make these more useful to read, let me know.

Note: if someone would like to make use of these slides, please acknowledge me. I would be happy to share the original .pptx files on request (email).

2015-09-21: fixed some typos that gave extra e^2 factors in the classically-calculated spontaneous emission rate. Notes are updated.

This list is from 2015.

These downloads require Adobe Acrobat Reader Class 1: introduction Classes 2 and 3: waves, simple resonators and blackbody radiation Class 4: Quantum Mechanics and transitions Class 5: line shapes and cross-sections Class 6: absorption and gain Class 7: rate equations and Einstein A,B coefficients Class 8: line broadening and saturation Classes 9 and 10: EM waves and interference 5Oct: includes new section on geometrical optics review

The list of notes shown below is from 2013 - updated notes will be added throughout the semester.

These downloads require Adobe Acrobat Reader Class 1: introduction Class 2: waves, EM waves, energy density Classes 2-6: full set of notes Class 7: material response to EM waves. We didn't finish all of these on Wedenesday. QM approach to transitions, natural, doppler and collisional broadening saturation, gain, and amplifiers interference and interferometers raytracing, intro to diffractive propagation diffraction and Gaussian beams resonator design unstable resonators, generalized ABCD equations for laser operation, threshold threshold, output coupling, pumping efficiency considerations

Mathematica Demos

These aren't actually pdf's. Do a "save link as" to save these to your computer, then open with Mathematica.

These downloads require Adobe Acrobat Reader Spectral_shapes.nb : shows BB radiation curves vs frequency and wavelength, also compare Gaussian and Lorentzian shapes fresnel_eqns.nb : interactive plots relating to the Fresnel equations for reflection, transmission at a dielectric interface Polarization_tools.nb : polarization vectors and matrices Fabry-Perot_etalon.nb : interactive plots relating to the Fabry-Perot etalon OC_optimization.nb : Optimizing output coupling in a CW oscillator ABCD_raytracing.nb : ABCD matrices for raytracing, including functions for plotting rays and setting up a sequence ABCD_cavity_analysis_class.nb : ABCD matrices for Gaussian beams and resonators Laser Canvas 5: zip file for a Windows program written at CSU. This program is usable but is not supported.

Useful Links

Photonics.com article on history of lasers

APS article on Townes laser inventions

Javan and Bennet invent HeNE laser

Lab design information

Computer software for lab equipment

You can load the software for the power meter using this website:

PM100 software

This should work for any version of Windows.

The camera software is at this site:

Camera software

This only works on Windows 7.

For later versions of Windows (at least 8), this driver should work. [2]

Thorlabs Fabry-Perot interferometer

These downloads require Adobe Acrobat Reader data sheet for the Thorlabs Fabry Perot manual for FP driver.

Diode-pumped solid state laser

These downloads require Adobe Acrobat Reader data sheet for 2300 series 808nm pump laser for DPSS

Thermistor calculator to convert measured resistance to temperature thermistor calculator

Compass 215M single longitudinal mode green laser

These downloads require Adobe Acrobat Reader data sheet for 5V power supply for Compass control module

External cavity diode laser

These downloads require Adobe Acrobat Reader data sheet for diode laser

Links

Wavelength Electronics: Spec page for diode power cable spec page

Siskiyou: Spec page for flexure mirror mount flexure mount page

Thorlabs: diode collimation tube collimation page