The goal of our project is to be able to resolve and characterize an input optical pulse train in terms of amplitude and
phase. These input optical pulses are low-energy (>100 pJ) and are short in duration (picoseconds – 100’s of
femtoseconds). Due to the low-energy nature of these pulses, we can not use pre-established means such as frequencyresolved optical gating (FROG) to characterize these pulse trains. The pulse train to-be-characterized will be electrically
gated utilizing a photodiode and the amount of pulse overlapping is adjusted via changing the variable time delay line.
The plot of the variation in time-delay within the second arm, the output spectrum of the overlapped pulses, and the
intensity at each wavelength in the spectrum is called a spectrogram. This spectrogram is deconvolved back to the timedomain to retrieve the pulse information.
The optical design in this system includes the optimization of the fiber lengths between the primary and secondary arms of
the FREG, optimizing the beam-splitter power ratio, designing sufficient pulse overlapping in terms of optical output
power and the design of the Czerny-Turner optical spectrum analyzer which builds a spectrogram for deconvolution.
The application of our system is for the characterization of low-energy femtosecond lasers which are used in the medical
field and in telecommunications. These devices will be built by the lab we are sponsored by, thus the need for the
characterization of them.
There are no commercially available systems which utilize FREG. There are commercially available FROG systems, but
as previously stated, this does not meet the demands of the application.
Project Website
(Must be on UCF WIFI or VPN to access)Advisors: Dr. Andrea Blanco-Redondo and Dr. Darren Hudson
Sponsor: Dr. Andrea Blanco-Redondo