Carrier-Envelope Phase

by Brett Chrisler

        Advisor:  Vinod Kumarappan, Associate Professor of Physics

Kansas State University Physics Department  REU Program

Project Overview Research Description and Progress  Final Presentation Lectures  Ethics class About Me


Project Overview: 

Mode-locked femtosecond lasers create a sequence of pulses. With a moving pulse, the carrier-wave and the envelope travel at different velocities, the first with the phase velocity and the later with the group velocity. The difference between these two results in the carrier-envelope phase shift and the offset frequency between them needs to be obtained and stabilized. In this experiment, we used a self-referencing f-to-2f interferometer to obtain this offset frequency.

Additionally, I assisted on a pump-probe laser experiment to research electron diffraction of aligned molecules. This setup required a laser beam to be separated into two paths, one of which is called the pump and the other probe. The two beams later overlapped and crossed with a gas jet inside a vacuum chamber. The delay between the pump and the probe can be changed after the spatial and temporal overlaps are discovered. The pump vibrates the molecules in the gas, and then the probe ionizes these molecules. The electrons that are stripped are sent through a microchannel plate onto a velocity map imaging system and recorded by a camera.


Research Description and Progress


For a full description and progress view my final presentation and Eric Wayne Moon’s abstract of a dissertation Carrier-Envelope Phase Stabilization of Grating-Based Chirped-Pulse Amplifiers.”


Final Presentation: 

Click here to download my presentation in PowerPoint and pdf formats.



Since there were a variety of topics covered during lectures, I gained knowledge in all fields of physics. Every presentation contained exciting material that kept me engaged. All the instructors that presented were extremely informative on their topics. I struggled to understand some of the topics in the quantum mechanics area, but I know learning some knowledge about these topics will only assist me in my future courses.


Ethics Class:

Ethics class was run by Professors Bruce Glymour and Amelica Hicks. I gained knowledge in many areas in ethics: guidlines, diversity, plagiarism, fraud, co-authorship, framing, advocacy, and mentoring. Every class was open for discussion to gain different viewpoints, which allowed everyone in the program to have input on the topics presented.


About Me:

I attend Fort Hays State University and I am an undergraduate pursuing my B.S. in physics. Furthermore, I am a tutor for the department and Secretary of the Physics Club. I first became interested in physics when I wanted to obtain a degree in meteorology and atmoshperic science. Now, I hope to pursue a career in medical physics or radiation oncology. In my free time, I love to run, sing, and socialize with friends and new people.


Future REU Students:

I would highly recommend the REU program to any undergraduate student that wants to experience research. The K-State REU program gave me insight on what happens on a graduate school level in the laboratory and also allowed me to gain knowledge in many areas of physics. Furthermore, the other students I met on this summer program I gained amazing friendships with that allowed for personal, academic, and professional growth. There has not been a better opportunity than this undergraduate program so far in my college career, and I would definitely want to have this experience again if given the chance.

This program is funded by the National Science Foundation through grant number PHYS-1461251.  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Useful Links: 

I have found the following links particularly informative or useful:

American Physical Society Statements on Ethics

American Institute of Physics