Low Cost Ultrafast Optics with a Mode-Locked Erbium Fiber Laser
Bethel University, June 13–15, 2018
Immersion participants will build and characterize a connector-based, mode-locked erbium fiber laser. We will carefully align a polarizer and a series of wave plates in a free-space segment of the cavity (see figure below) to optimize conditions for pulses. Output pulses from such a laser can be on the order of 100 fs and are strongly influenced by the cavity dispersion properties. The Fourier transform of a train of pulses is a relatively broad spectrum (tens of nanometers) of individual frequencies separated by the cavity pulse repetition rate. When stabilized and broadened, this comb of frequencies acts like millions of stable lasers and can be used for applications such as frequency metrology. Participants will align and use an auto-correlation device to characterize the temporal profile and chirp of output pulses. The auto-correlator uses the nonlinear response of a silicon photodetector at the lasing wavelength of 1.5 micrometers, which helps make it affordable.
(One set-up) CLOSED
Follow this link to watch a video overview of this Immersion.
Host and Mentor:
Chad Hoyt is Associate Professor of Physics at Bethel University. Dr. Hoyt earned his Ph.D. in Optical Science from the University of New Mexico in 2003. His research comprised the first demonstration and analysis of optical cooling of thulium-doped solids. Chad has experience in laser cooling and trapping, as well as atomic, molecular and optical physics. He did post-doctoral work at the National Institute of Standards and Technology in Boulder, CO in the field of optical atomic clocks from 2003-2006. He helped build a system for cooling, trapping and spectroscopically probing ytterbium atoms with high precision. Since coming to Bethel University in 2006, Chad and his undergraduate research team have constructed a lithium magneto-optical trap and made spectroscopic measurements of the atoms at ∼500 microkelvin. Chad has helped develop and lead advanced lab-based courses in Optics and Lasers. Open-ended student projects in these courses have included nonlinear optics (Z-scan measurements, parametric downconversion), atomic and molecular spectroscopy, laser cooling and trapping, building HeNe lasers, holographic and interferometric measurements, quantum optics, fiber lasers, and precision measurements with physical optics. The fiber laser and frequency comb work is supported in part by NSF EIR grant #1208930.
Chad Hoyt, Associate Professor of Physics, Bethel University, Department of Physics, 3900 Bethel Dr. #2336, St. Paul, MN 55112. Email: firstname.lastname@example.org. Telephone: 651-638-6989.
Please note that the Jonathan F. Reichert Foundation has established a grant program to help purchase apparatus used in Laboratory Immersions. Limitations and exclusions apply, but generally speaking the foundation may support up to 40% of the cost of the required equipment.